A wire has a resistance of 12 Ω. It is bent in the form of a circle. The effective resistance between the two points on any diameter of the circle is A) 6 Ω B) 12 Ω C) 24 Ω D) 3 Ω
💡Correct Answer: Option D (3 Ω)
When a wire of total resistance 12 Ω is bent into a circle, any diameter divides the circle into two semicircular halves. The resistance of each semicircular path is R_half = 12 / 2 = 6 Ω. Since these two halves are connected in parallel between the diametrically opposite points, the equivalent resistance is R_eq = (6 * 6) / (6 + 6) = 36 / 12 = 3 Ω.
Q2
Electrical EngineeringNetwork Theorems (Maximum Power Transfer)
What percentage of the maximum Power is delivered to R_L in the given figure, when R_L = 2 R_Th? A) 75 % B) 90 % C) 88.89 % D) None of the above
💡Correct Answer: Option C (88.89 %)
Maximum power delivered to load occurs when R_L = R_Th, given by P_max = V_Th^2 / (4 R_Th). When R_L = 2 R_Th, current I = V_Th / (R_Th + 2 R_Th) = V_Th / (3 R_Th). Power delivered P_L = I^2 R_L = (V_Th / 3 R_Th)^2 (2 R_Th) = 2 V_Th^2 / (9 R_Th). The ratio is P_L / P_max = [2 / 9] / [1 / 4] = 8 / 9 = 0.8889, which corresponds to 88.89%.
The electric field intensity on the surface of a charged conductor is A) Zero B) Directed normally to the surface C) Directed tangentially to the surface D) Directed at 45° to the surface
💡Correct Answer: Option B (Directed normally to the surface)
In electrostatics, the surface of a charged conductor is an equipotential surface. Any tangential component of electric field would cause surface charges to accelerate, violating electrostatic equilibrium. Therefore, the electrostatic field intensity immediately outside the surface of a charged conductor is always directed perpendicular (normal) to the surface (E = σ/ε_0).
64 drops of radius r combine to form a bigger drop of radius R. The ratio of the capacitances of the bigger to the smaller drop is A) 1:4 B) 4:1 C) 1:2 D) 2:1
💡Correct Answer: Option B (4:1)
Conservation of volume: (4/3)π R^3 = 64 * (4/3)π r^3 => R^3 = 64 r^3 => R = 4r. The capacitance of an isolated spherical conductor in free space is directly proportional to its radius (C = 4πε_0 r). Therefore, C_bigger / C_smaller = R / r = 4r / r = 4:1.
Q5
Electrical EngineeringMagnetic Circuits
In the figure, the cross-section of the core is circular and has a radius of 1.25 mm. The mean length of the core is 30 cm. If the flux in the core is 0.6 × 10^(-5) Wb, then H in air-gap is: A) 2.5 × 10^6 AT/m B) 1.5 × 10^7 AT/m C) 8.2 × 10^4 AT/m D) 9.71 × 10^5 AT/m
💡Correct Answer: Option D (9.71 × 10^5 AT/m)
Cross-sectional area A = π r^2 = π (1.25 × 10^(-3))^2 = 4.9087 × 10^(-6) m^2. Magnetic flux density B = Φ / A = (0.6 × 10^(-5)) / (4.9087 × 10^(-6)) = 1.2223 T. In the air gap, permeability is μ_0 = 4π × 10^(-7) H/m. Magnetic field intensity H_gap = B / μ_0 = 1.2223 / (4π × 10^(-7)) = 9.726 × 10^5 AT/m ≈ 9.71 × 10^5 AT/m. Hence, Option D is correct.
Q6
Electrical EngineeringElectromagnetic Induction
A solenoid consisting of 2000 turns is uniformly wound over a length of 0.3 meters and has a cross-sectional area of 1.2 × 10^(-3) m^2. A secondary coil with 300 turns is closely wound around the central region of the solenoid. If the current in the solenoid, initially 2 A, is reversed in 0.25 seconds, what is the magnitude of the e.m.f. induced in the secondary coil? A) 0.048 V B) 1.2 V C) 1.9 V D) 0.023 V
💡Correct Answer: Option A (0.048 V)
Mutual inductance M = (μ_0 N1 N2 A) / l = (4π × 10^(-7) 2000 300 1.2 × 10^(-3)) / 0.3 = 3.016 × 10^(-3) H. Current reversal means ΔI = 2 - (-2) = 4 A in Δt = 0.25 s => dI/dt = 4 / 0.25 = 16 A/s. Induced EMF e = M (dI/dt) = 3.016 × 10^(-3) 16 = 0.04825 V ≈ 0.048 V.
Q7
Electronics & CommunicationSignals and Systems (DTFT)
If the Fourier Transform of x[n] is X(e^(jω)), then what will be the Fourier Transform of x[-n]?
A) X(e^(-jω)) B) X(e^(jω))
C) X(-e^(-jω)) D) X*(-e^(jω))
💡Correct Answer: Option B (X*(e^(jω)))
By the properties of the Discrete-Time Fourier Transform (DTFT): time reversal gives x[-n] <-> X(e^(-jω)), and complex conjugation gives x[n] <-> X(e^(-jω)). Applying both properties simultaneously yields the time-reversal conjugation property: x[-n] <-> X(e^(jω)). Hence, Option B is correct.
Q8
Electrical EngineeringSignals and Systems
For a periodic signal v(t) = 30 sin(100t) + 10 cos(300t) + 6 sin(500t + π/4), the fundamental frequency in rad/s is A) 300 B) 450 C) 100 D) 720
💡Correct Answer: Option C (100)
The individual harmonic frequencies present in the composite signal are ω_1 = 100 rad/s, ω_2 = 300 rad/s, and ω_3 = 500 rad/s. The fundamental frequency ω_0 is the greatest common divisor (GCD) of the constituent frequencies: ω_0 = GCD(100, 300, 500) = 100 rad/s.
Q9
Electrical EngineeringPower Systems & Protection
What type of current transformer (CT) connection is used for the protection of a star-delta connected three-phase power transformer? A) Delta-Star B) Star-Star C) Star-Delta D) Delta-Delta
💡Correct Answer: Option A (Delta-Star)
In differential protection of power transformers, current transformers (CTs) on the star side of the power transformer are connected in delta, and CTs on the delta side of the power transformer are connected in star (Delta-Star connection). This reverse CT connection compensates for the inherent 30° phase shift introduced between the primary and secondary line currents of a star-delta power transformer.
On which of the following factors does hysteresis loss depend? i. Flux density ii. Frequency iii. Thickness of laminations iv. Time Select the correct answer from the options given below. A) ii and iii B) i and iv C) iii and iv D) i and ii
💡Correct Answer: Option D (i and ii)
By Steinmetz's empirical formula, hysteresis loss per unit volume is P_h = η (B_max)^x f, where B_max is maximum flux density and f is frequency. Thickness of laminations reduces eddy current loss (P_e ∝ t^2), not hysteresis loss. Thus, hysteresis loss depends on flux density (i) and frequency (ii). Option D is correct.
Q11
Electrical EngineeringDC Machines
A DC series motor is driving a load for which the torque varies proportionally to the square of the speed. If the motor draws a line current of 10 A at 200 rpm, what will be the line current when the speed increases to 400 rpm? A) 15.5 A B) 20 A C) 10.14 A D) 14.14 A
💡Correct Answer: Option B (20 A)
For a DC series motor (unsaturated), torque T ∝ I^2, and back EMF E_b ∝ N Φ ∝ N I. For constant supply voltage V ≈ E_b ∝ N I => N ∝ 1/I. Alternatively, torque T_load ∝ N^2. With T_motor ∝ I^2, equating gives I^2 ∝ N^2 => I ∝ N. When speed doubles from 200 rpm to 400 rpm, line current also doubles: I_2 = I_1 (N_2 / N_1) = 10 * (400 / 200) = 20 A.
Q12
Electrical EngineeringPower System Analysis (Per-Unit System)
A synchronous generator has a direct-axis reactance X_d = 0.4 per unit, based on its nameplate ratings of 10 kV and 75 MVA. If the per-unit reactance is to be recalculated on a new base of 11 kV and 100 MVA, what will be the new per-unit value of X_d? A) 0.54 B) 0.28 C) 0.44 D) 0.38
A 400 V, 15 kW, 4-pole, 50 Hz Y-connected induction motor has a full-load slip of 4%. The output torque of the machine at full load is: A) 99.47 N B) 98.53 N C) 99.47 Nm D) 98.53 Nm
Consider the following statements regarding HVDC system: i. The modern HVDC systems use 12-pulse converters ii. DC systems never use ground or sea return iii. Most of the present-day DC schemes are two-terminal links Which of the statements given above is/are correct? A) i and iii only B) i only C) i, ii and iii D) ii and iii only
💡Correct Answer: Option A (i and iii only)
Statements (i) and (iii) are correct: Modern HVDC systems universally use 12-pulse thyristor/IGBT converters to eliminate 5th and 7th harmonics (i), and the vast majority of operational HVDC schemes are point-to-point two-terminal links (iii). Statement (ii) is false because monopole HVDC links regularly utilize ground or sea return for continuous or emergency return paths. Hence, i and iii only (Option A) is correct.
A generating station has a maximum demand of 30 MW, a load factor of 60% and a plant capacity factor of 50%. The reserve capacity of the plant is: A) 5 MW B) 4 MW C) 3 MW D) 6 MW
If x and y are Boolean variables, which one of the following is the equivalent of x ⊕ y ⊕ xy? A) x + y' B) x + y C) 1 D) 0
💡Correct Answer: Option B (x + y)
Let F = x ⊕ y ⊕ xy. Evaluating by truth table: When (x, y) = (0, 0): F = 0 ⊕ 0 ⊕ 0 = 0. When (x, y) = (0, 1): F = 0 ⊕ 1 ⊕ 0 = 1. When (x, y) = (1, 0): F = 1 ⊕ 0 ⊕ 0 = 1. When (x, y) = (1, 1): F = 1 ⊕ 1 ⊕ 1 = 0 ⊕ 1 = 1. The output truth table gives (0, 1, 1, 1), which is the exact truth table of the Boolean OR operation (x + y).
Q17
Electronics & CommunicationSemiconductor Devices (MOS vs Bipolar)
Which of the following statements is NOT correct? A) MOS devices require fewer manufacturing cycles B) MOS devices are the fastest devices C) MOS gates dissipate less power per gate D) MOS gates require less space on the silicon wafer
💡Correct Answer: Option B (MOS devices are the fastest devices)
Bipolar devices (such as ECL - Emitter Coupled Logic) and modern Gallium Arsenide/SiGe devices are inherently faster than MOS devices due to high transconductance and minority carrier transport dynamics. Statement B ('MOS devices are the fastest devices') is factually incorrect.
Q18
Electrical EngineeringPower Electronics & Devices
Match the two lists and choose the correct answer from the codes given below: List - I (Types of Device) (w) MOSFET (x) GTO (y) UJT (z) TRIAC
List - II (Characteristics/Application) (i) Turn off by negative gate (ii) Bidirectional switching (iii) High-speed switching (iv) Triggering circuit
Choose the correct option: A) (w)-(iii), (x)-(i), (y)-(iv), (z)-(ii) B) (w)-(ii), (x)-(iii), (y)-(iv), (z)-(i) C) (w)-(ii), (x)-(iv), (y)-(i), (z)-(iii) D) (w)-(iii), (x)-(i), (y)-(ii), (z)-(iv)
💡Correct Answer: Option A ((w)-(iii), (x)-(i), (y)-(iv), (z)-(ii))
Matching semiconductor devices: (w) MOSFET is a unipolar majority-carrier device known for high-speed switching (iii); (x) GTO (Gate Turn-Off Thyristor) can be turned off by applying a negative gate pulse (i); (y) UJT (Uni-Junction Transistor) is classically used in relaxation oscillators for thyristor triggering circuits (iv); (z) TRIAC is a bidirectional thyristor capable of conducting current in both directions (ii). Hence, Option A is correct.
Q19
Electrical EngineeringControl Systems (Block Diagram Reduction)
The block diagram for a particular control system is shown in the figure. What is the transfer function C(s)/R(s) for this system? [Figure shows forward branch with integrator s^(-1) with numerator gain 'a' in parallel forward and inner feedback 'b'] A) (s + a) / (s - b) B) (s - b) / (s + b) C) (s + a) / (s + b) D) (s + b) / (s + a)
💡Correct Answer: Option C ((s + a) / (s + b))
Applying Mason's gain formula or standard block diagram reduction: the forward paths are P_1 = 1 and P_2 = a/s, so numerator is 1 + a/s = (s + a)/s. The feedback loop has loop gain -b/s, so denominator is 1 - (-b/s) = 1 + b/s = (s + b)/s. The overall closed-loop transfer function is C(s)/R(s) = [(s + a)/s] / [(s + b)/s] = (s + a) / (s + b).
Q20
Electrical EngineeringControl Systems
A negative feedback closed-loop system is supplied with an input of 5 V. The system has a forward gain of 1 and a feedback gain of 1. What is the output voltage? A) 2.5 V B) 1.0 V C) 1.5 V D) 3.0 V
💡Correct Answer: Option A (2.5 V)
Closed-loop transfer function with negative feedback is T = G / (1 + GH). Given forward gain G = 1 and feedback gain H = 1: T = 1 / (1 + 11) = 1 / 2 = 0.5. With input V_in = 5 V, the output voltage is V_out = T V_in = 0.5 5 V = 2.5 V.
Q21
Electrical EngineeringNetwork Theorems
In the circuit shown below, when Vs = 0V, I = 3A. What will be the value of I when Vs = 12 V? A) 7 A B) 3 A C) 9 A D) 6 A
💡Correct Answer: Option D (6 A)
By the Superposition Theorem: I = I_current_source + I_voltage_source. When Vs = 0V, current is I = 3A, representing the contribution of the independent current source alone. When Vs = 12 V is activated with the current source opened, the two 2 Ω resistors and the branch 2 Ω form a bridge/mesh delivering an additional current of 12 V / (2 + 2) = 3 A through the central branch. Total current I = 3 A + 3 A = 6 A. Hence, Option D is correct.
Two coupled coils of L1 = 0.8 H and L2 = 0.2 H have a coupling coefficient of k = 0.9. The mutual inductance M is: A) 0.144 H B) 0.36 H C) 0.23 H D) 0.43 H
💡Correct Answer: Option B (0.36 H)
Mutual inductance is given by M = k √(L1 L2). Substituting: M = 0.9 √(0.8 0.2) = 0.9 √(0.16) = 0.9 0.4 = 0.36 H.
Q23
Electronics & CommunicationSignals & Systems (Fourier Transform)
A signal x(t) has a Fourier transform X(jω). If x(t) is a real and odd function of t, then X(jω) is A) A real and even function of ω B) An imaginary and even function of ω C) An imaginary and odd function of ω D) A real and odd function of ω
💡Correct Answer: Option C (An imaginary and odd function of ω)
By Fourier transform symmetry properties: if a continuous-time signal x(t) is real and odd [x(-t) = -x(t) and x(t) = x(t)], its Fourier transform X(jω) is purely imaginary and an odd function of ω [X(-jω) = -X(jω) = X(jω)].
Q24
Electrical EngineeringControl Systems & Laplace Transforms
The output of a linear system for a step input is t^2 e^(-2t). The transfer function of the system is: A) 2s / (s + 2)^3 B) s / (s + 1)^3 C) 3s / (s + 2)^2 D) s / [s^2 (s + 1)^3]
💡Correct Answer: Option A (2s / (s + 2)^3)
Output y(t) = t^2 e^(-2t) u(t). The Laplace transform of y(t) is Y(s) = 2! / (s + 2)^3 = 2 / (s + 2)^3. For a unit step input x(t) = u(t), X(s) = 1/s. The transfer function H(s) = Y(s) / X(s) = [2 / (s + 2)^3] / [1/s] = 2s / (s + 2)^3.
Q25
Electronics & CommunicationSemiconductor Physics
An intrinsic semiconductor has an intrinsic electron concentration of 10^16 m^(-3). It is doped with donor atoms to a concentration of 10^22 m^(-3), with all donors fully ionised. What is the resulting hole concentration in the semiconductor? A) 10^22 m^(-3) B) 10^16 m^(-3) C) 10^11 m^(-3) D) 10^10 m^(-3)
💡Correct Answer: Option D (10^10 m^(-3))
By the Mass Action Law in semiconductors, n * p = n_i^2 at thermal equilibrium. Here, n_i = 10^16 m^(-3), and donor concentration n ≈ N_D = 10^22 m^(-3). Therefore, hole concentration p = n_i^2 / n = (10^16)^2 / 10^22 = 10^32 / 10^22 = 10^10 m^(-3).
Which of the following features are offered by a bipolar junction transistor amplifier in Darlington connection? i. High voltage gain ii. High input impedance iii. High current gain Select the correct answer using the code given below. A) i and ii only B) ii and iii only C) i and iii only D) i, ii and iii
💡Correct Answer: Option B (ii and iii only)
A Darlington pair configuration provides an extremely high composite current gain (β_total ≈ β1 β2) and very high input impedance (R_in ≈ β1 β2 * R_E), while its voltage gain remains less than or close to unity (A_v ≈ 1). Thus, it offers high input impedance (ii) and high current gain (iii), but NOT high voltage gain. Option B is correct.
Q27
Electronics & CommunicationOperational Amplifiers
An op-amp circuit is shown in the given figure. The current I is: [Op-amp 741 with non-inverting input at +2 V, inverting input connected to emitter of NPN transistor with 1 kΩ load to ground, and collector tied to +12V via 1 kΩ] A) 10 mA B) 0 mA C) 6 mA D) 12 mA
💡Correct Answer: Option B (0 mA)
Due to infinite input impedance of the op-amp, input current is 0 mA, or under cut-off conditions current I is 0 mA. Hence, Option B is correct.
Q28
Electronics & CommunicationOscillators
Consider the following statements: i. A Hartley oscillator circuit uses a tapped inductor for inductive feedback ii. An oscillator circuit can be operated in class A condition for better waveshape iii. Frequency stabilisation is obtained by the use of automatic biasing Which of the statements given above are correct? A) ii and iii B) i and iii C) i and ii D) i, ii and iii
💡Correct Answer: Option C (i and ii)
Statements (i) and (ii) are correct: A Hartley oscillator famously uses a center-tapped inductor (or two inductors) in its tank circuit for positive inductive feedback (i); and operating in Class A bias yields minimal harmonic distortion and superior sinusoidal waveshape (ii). Automatic biasing stabilizes amplitude, not frequency (frequency is stabilized by high-Q crystal or tuned circuits). Thus, i and ii (Option C) is correct.
A 12-bit A/D converter has a range of 0-10 V. What is the approximate resolution of the converter? A) 0.488 mV B) 2.44 mV C) 4.88 mV D) 0.244 mV
💡Correct Answer: Option B (2.44 mV)
Resolution = Full Scale Voltage / (2^n - 1) = 10 V / (2^12 - 1) = 10 V / 4095 = 0.002442 V = 2.44 mV.
Q31
Computer Science & ITMicroprocessors & Bus Arbitration
Which type of control pins are used in a microprocessor to regulate access to the bus and prevent multiple devices from using it simultaneously? A) Bus Request (BR) and Bus Grant (BG) pins B) Interrupt Request (IRQ) and Interrupt Acknowledge (INTA) pins C) Read (RD) and Write (WR) pins D) Clock (CLK) and Reset (RST) pins
💡Correct Answer: Option A (Bus Request (BR) and Bus Grant (BG) pins)
Bus arbitration control signals—such as HOLD / HLDA in 8085 or Bus Request (BR) and Bus Grant (BG) in microprocessors—are used to mediate and regulate control of the shared system bus between the CPU and DMA controllers/co-processors, preventing bus contention.
The READY signal in 8085 is useful when the CPU communicates with A) A fast peripheral device B) A DMA controller chip C) A slow peripheral device D) A PPI chip
💡Correct Answer: Option C (A slow peripheral device)
The READY input pin on the 8085 microprocessor is used to synchronize the high-speed CPU with slower memory or peripheral devices. If the READY line is low, the CPU inserts WAIT states into its bus machine cycle until the slow peripheral completes data transfer and drives READY high.
Q33
Electrical EngineeringControl Systems (Time Domain Analysis)
For a second-order system, the natural frequency of oscillation is 10 rad/s, and the damping ratio is 0.1. What is the 2% settling time? A) 2 s B) 2.5 s C) 3.2 s D) 4 s
💡Correct Answer: Option D (4 s)
The settling time for a 2% tolerance band in a standard second-order system is given by t_s = 4 / (ζ ω_n). Substituting given values: t_s = 4 / (0.1 10) = 4 / 1 = 4 seconds.
Q34
Electrical EngineeringControl Systems (Feedback Characteristics)
Consider the following statements concerning a feedback control system: i. Accuracy cannot be obtained by adjusting the loop gain ii. Feedback decreases overall gain iii. Introduction of noise due to a sensor increases the overall gain iv. Introduction of feedback may lead to the possibility of instability in a closed-loop system Which of the statements given above is/are correct? A) i and iii B) ii and iv C) i and iv D) ii and iii
💡Correct Answer: Option B (ii and iv)
Fundamental properties of negative feedback: (ii) Negative feedback reduces overall system gain by a factor of (1 + GH); and (iv) High gain or excessive phase lag in feedback can push closed-loop poles into the right half of the s-plane, causing instability. Thus, ii and iv (Option B) is correct.
Q35
Electronics & CommunicationCommunication Systems (AM Modulation)
The number of AM broadcast stations that can be accommodated in a 100 kHz bandwidth for the highest modulating frequency of 5 kHz will be: A) 10 B) 20 C) 100 D) 5
💡Correct Answer: Option A (10)
Bandwidth required for one standard double-sideband Amplitude Modulated (AM) station is BW = 2 f_m, where f_m is the highest modulating frequency: BW = 2 5 kHz = 10 kHz. In a total allocated channel bandwidth of 100 kHz, the number of stations accommodated is N = Total Bandwidth / Bandwidth per station = 100 kHz / 10 kHz = 10 stations.
Q36
Electronics & CommunicationCommunication Systems (FM & Noise)
In which of the following modulations can the signal-to-noise ratio be improved by increasing bandwidth? A) AM B) FM C) SSB D) DSB-SC
💡Correct Answer: Option B (FM)
Frequency Modulation (FM) allows an explicit trade-off between transmission bandwidth and noise performance: by increasing the frequency deviation Δf (which increases the modulation index β and bandwidth), the output Signal-to-Noise Ratio (SNR) improves proportionally to the square of the modulation index (SNR ∝ β^2). In AM systems, increasing bandwidth admits more channel noise without improving SNR.
During the frequency conversion (heterodyning) in a superheterodyne receiver, the original modulation on the signal: A) Is completely removed B) Is reduced in amplitude C) Is shifted to a new frequency but remains unchanged D) Is distorted and lost
💡Correct Answer: Option C (Is shifted to a new frequency but remains unchanged)
In a superheterodyne receiver mixer stage, the incoming RF signal is heterodyned (multiplied) with a local oscillator signal to produce the fixed Intermediate Frequency (IF). The mixer translates/shifts the carrier spectrum down to the IF while preserving all original amplitude, frequency, and phase modulation without distortion.
Q38
Electronics & CommunicationDigital Communication (Delta Modulation)
In delta modulation, slope overload occurs when the modulating signal changes: A) Less rapidly than the encoder can follow B) More rapidly than the encoder can follow C) Independent of any changes in the signal D) None of the above
💡Correct Answer: Option B (More rapidly than the encoder can follow)
Slope overload distortion in Delta Modulation occurs when the maximum rate of change (slope) of the modulating analog signal exceeds the maximum tracking slope capability of the staircase approximation (i.e. |dm(t)/dt| > Δ / T_s, where Δ is the step size and T_s is sampling interval).
The radio horizon distance increases if: A) The antenna height increases B) The frequency of the signal increases C) The antenna is moved closer to the ground D) The antenna height decreases
💡Correct Answer: Option A (The antenna height increases)
In space-wave line-of-sight (LOS) propagation, the optical and radio horizon distance is given by d ≈ √(2 k R_earth h) ≈ 4.12 √h km (where h is antenna height in meters). As the physical antenna height increases, the line-of-sight distance over the curved earth increases.
In a dipole array, the overall radiation pattern does not depend upon: A) Directional patterns of the elements B) Spacing between the elements C) Phase difference between the various feed points D) None of the above
💡Correct Answer: Option D (None of the above)
By the Principle of Pattern Multiplication, the overall radiation field pattern of an antenna array is the product of the individual element pattern and the array factor: Total Pattern = (Element Pattern) × (Array Factor). The Array Factor depends directly on the number of elements, physical spacing (d), and progressive excitation phase difference (α). Therefore, the overall radiation pattern depends on ALL three listed factors, making 'None of the above' (Option D) the correct answer.
Q41
Renewable Energy & EnvironmentRenewable Energy & Environment
Consider the following statements regarding green hydrogen: i. It can be used directly as a fuel for internal combustion ii. It can be blended with natural gas and used as fuel for heat or power generation iii. It can be used in the hydrogen fuel cell to run vehicles Which of the statements given above is/are correct? A) i only B) ii only C) ii and iii only D) i, ii and iii
💡Correct Answer: Option D (i, ii and iii)
Green hydrogen (produced by water electrolysis using renewable power) is extremely versatile: (i) It can be directly combusted in modified internal combustion engines (H2-ICE); (ii) It can be blended with natural gas (up to 15-20% without pipeline retrofitting) for heating and power; and (iii) It is utilized in Proton Exchange Membrane (PEM) fuel cells to power electric vehicles emission-free. Hence, all statements i, ii, and iii are correct.
Q42
Renewable Energy & EnvironmentRenewable Energy & Environment
Consider the following: i. Battery storage ii. Biomass generators iii. Fuel cells iv. Rooftop solar photovoltaic units Which of the above is/are considered a "Distributed Energy Resource"? A) i only B) i, ii, iii and iv C) ii and iii D) i, ii and iv
💡Correct Answer: Option B (i, ii, iii and iv)
Distributed Energy Resources (DERs) are small-scale, decentralized electricity supply or demand management resources that are interconnected to the local distribution system or installed behind the meter. They include battery energy storage systems (BESS), biomass power units, fuel cells, and rooftop solar PV installations. Therefore, all i, ii, iii, and iv are DERs.
Q43
Renewable Energy & EnvironmentRenewable Energy & Environment
The term "pumped-storage hydropower" has been recently highlighted in the context of which of the following? A) Irrigation of terraced agricultural land B) Lift irrigation for cereal crop cultivation C) Long-duration storage of electrical energy D) Rainwater collection and harvesting systems
💡Correct Answer: Option C (Long-duration storage of electrical energy)
Pumped-storage hydropower (PSH) functions as a giant gravitational 'water battery'. It stores electrical energy during low demand/excess renewable generation periods by pumping water from a lower reservoir to an upper reservoir, and generates electricity during peak demand by releasing it back through turbines, providing cost-effective long-duration grid energy storage.
Q44
Renewable Energy & EnvironmentRenewable Energy & Environment
With reference to solar water pumps, consider the following statements: i. Solar power can be used for running surface pumps, except submersible pumps ii. Solar power can be used for running centrifugal pumps, except those with a piston Which of the statements given above is/are correct? A) i only B) ii only C) Both i and ii D) Neither i nor ii
💡Correct Answer: Option D (Neither i nor ii)
Both statements are incorrect. Solar photovoltaic power can easily run both surface pumps AND submersible deep-well pumps. Similarly, solar PV systems can drive centrifugal pumps as well as positive displacement piston/reciprocating pumps. Thus, neither i nor ii is correct.
Q45
Renewable Energy & EnvironmentRenewable Energy & Environment
Biomass gasification is considered to be one of the sustainable solutions to the power crisis in India. In this context, which of the following statements is/are correct? i. Coconut shells, groundnut shells and rice husk can be used in biomass gasification ii. The combustible gases generated from biomass gasification consist of hydrogen, argon and carbon dioxide iii. The combustible gases generated from biomass gasification can be used for direct heat generation Select the correct answer using the codes given below: A) i only B) ii and iii only C) i and iii only D) i, ii and iii
💡Correct Answer: Option C (i and iii only)
Statement i is correct because agricultural residues like coconut shells, groundnut shells, and rice husk are widely used biomass feedstocks. Statement ii is incorrect because producer gas (syngas) primarily contains CO, H2, CH4, and N2/CO2; argon is an inert trace atmospheric gas and not a major component, nor is CO2 combustible. Statement iii is correct because syngas can be burned directly for thermal/heat applications. Hence, i and iii only are correct.
Q46
Renewable Energy & EnvironmentRenewable Energy & Environment
Microbial fuel cells are considered a source of sustainable energy. Why? i. They use living organisms as catalysts to generate electricity from certain substrates ii. They use a variety of inorganic materials as substrates iii. They can be installed in wastewater treatment plants to cleanse water and produce electricity Which of the following statements given above is/are correct? A) i only B) ii and iii only C) i and iii only D) i, ii and iii
💡Correct Answer: Option C (i and iii only)
Microbial Fuel Cells (MFCs) use electrochemically active bacteria (living microorganisms) as biocatalysts to oxidize organic matter (not inorganic materials) and generate electric current (Statement i is correct, ii is incorrect). They are installed in municipal and industrial wastewater treatment plants to simultaneously treat sewage and generate bioelectricity (Statement iii is correct). Thus, statements i and iii only are correct.
Q47
Renewable Energy & EnvironmentRenewable Energy & Environment
The Ocean Thermal Energy Conversion (OTEC) uses: A) Energy difference B) Potential difference C) Kinetic difference D) Temperature difference
💡Correct Answer: Option D (Temperature difference)
Ocean Thermal Energy Conversion (OTEC) is a process that can produce electricity by using the temperature difference between deep cold ocean water (around 4-7°C at ~1000m depth) and warm tropical surface waters (around 25°C).
Q48
Renewable Energy & EnvironmentRenewable Energy & Environment
Ocean thermal energy conversion is characterised by having: A) High efficiency and low installation cost B) Low efficiency and high installation cost C) Low efficiency and low installation cost D) High efficiency and high installation cost
💡Correct Answer: Option B (Low efficiency and high installation cost)
Because the temperature difference between ocean surface water and deep water is relatively small (typically ~20°C), the theoretical Carnot cycle efficiency is very low (around 6-7%, with practical net efficiency around 2-4%). In addition, building offshore floating platforms and massive deep-sea cold water pipes leads to very high capital and installation costs.
Q49
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
Which of the following statements about surge tanks is INCORRECT? A) The ideal location of the surge tank is at the turbine inlet B) A decrease in load demand causes a rise in water level in the surge tank C) Surge tanks are completely closed to avoid the entry of unwanted objects into the penstock D) Surge tanks are installed to reduce the harmful effects of the water hammer phenomenon
💡Correct Answer: Option C (Surge tanks are completely closed to avoid the entry of unwanted objects into the penstock)
Surge tanks are open storage reservoirs (open to atmospheric pressure at the top) located near the turbine end of a long penstock. They absorb water hammer pressure transients during sudden closure of turbine valves and provide water during load pickup. They are NOT completely closed hermetic vessels.
Q50
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
A penstock in a hydroelectric power plant is: A) A conduit connecting the forebay to the scroll case of the turbine B) A nozzle that releases high-pressure water on turbine blades C) A pipe connected to the runner outlet D) A pipe connecting the surge tank to the dam
💡Correct Answer: Option A (A conduit connecting the forebay to the scroll case of the turbine)
A penstock is a large conduit (steel pipe or tunnel) that carries high-pressure water from the forebay or surge tank directly to the scroll casing / runner of the hydraulic turbine.
Q51
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
Which of the following is NOT a reaction turbine? A) Francis turbine B) Pelton wheel turbine C) Kaplan turbine D) Propeller turbine
💡Correct Answer: Option B (Pelton wheel turbine)
The Pelton wheel turbine is a tangential flow impulse turbine that operates under high head and low discharge, where all the pressure energy of water is converted into kinetic energy in nozzles before reaching the buckets. In contrast, Francis, Kaplan, and Propeller turbines are reaction turbines.
Q52
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
What is the runaway speed of the runner of the Pelton wheel? A) Maximum unsafe speed of the runner due to a sudden increase in load on the turbine B) Minimum safe speed of the runner due to a sudden decrease in load on the turbine C) Minimum safe speed of the runner due to a sudden increase in load on the turbine D) Maximum unsafe speed of the runner due to a sudden decrease in load on the turbine
💡Correct Answer: Option D (Maximum unsafe speed of the runner due to a sudden decrease in load on the turbine)
The runaway speed of a hydraulic turbine is the maximum speed attained by the runner under maximum head when the external load is suddenly dropped to zero and the governing mechanism fails to close the inlet valves/nozzles. Pelton wheel runners are designed structurally to withstand this maximum runaway speed (which can be 1.8 to 2 times rated speed).
Q53
Renewable Energy & EnvironmentRenewable Energy & Environment
Which type of windmill has better efficiency? A) Vertical type wind mills B) Darrieus type machines C) Horizontal type windmills D) Magnus effect rotor
💡Correct Answer: Option C (Horizontal type windmills)
Horizontal Axis Wind Turbines (HAWT) have higher aerodynamic power coefficients (efficiency up to 45-50%, close to the Betz limit of 59.3%) compared to vertical axis wind turbines (VAWT like Savonius or Darrieus) because their blades experience continuous aerodynamic lift throughout the full 360-degree rotation at higher elevations.
Q54
Renewable Energy & EnvironmentRenewable Energy & Environment
A two-blade wind turbine produces maximum power when the tip-speed ratio is approximately: A) 2π B) 0.473 C) 3π D) 0.593
💡Correct Answer: Option A (2π)
For modern two-bladed high-speed aerodynamic wind turbines, the optimal tip-speed ratio (λ = ωR / V) for maximum power coefficient is approximately λ ≈ 2π ≈ 6.28 (typically between 6 and 8). Note that 0.593 (16/27) is the theoretical Betz limit for maximum power extraction fraction, not the tip-speed ratio.
Q55
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
The power output from a hydroelectric power plant depends on which of the following parameters? A) Head, type of dam, and discharge B) Head, discharge, and efficiency of the system C) Efficiency of the system, type of draft tube, and type of turbine used D) Type of dam, discharge, and type of catchment area
💡Correct Answer: Option B (Head, discharge, and efficiency of the system)
The electrical power output of a hydro plant is governed by P = η ρ g Q H, where ρ is water density, g is acceleration due to gravity, Q is volumetric discharge (flow rate), H is net head, and η is the overall system efficiency.
Q56
Renewable Energy & EnvironmentEnergy Management & Conservation
What is the primary goal of energy management? A) Maximising energy consumption B) Optimising energy usage C) Minimising energy efficiency D) Reducing energy conservation
💡Correct Answer: Option B (Optimising energy usage)
The fundamental objective of energy management is to achieve and maintain optimum energy procurement and utilization throughout the organization, minimising energy costs and environmental impacts without affecting production, comfort, or quality.
Q57
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
Which factor is NOT typically considered in the selection of a site for a hydroelectric power station? A) Geological stability B) Vegetation density C) Water flow variability D) Wind speed
💡Correct Answer: Option D (Wind speed)
Selecting a site for a hydroelectric power station requires evaluating water flow availability, hydraulic head, geological stability of dam foundations, sedimentation, and catchment ecology/vegetation. Wind speed is relevant for wind farms, not hydroelectric stations.
Q58
Renewable Energy & EnvironmentEnergy Management & Conservation
What is the significance of lighting in energy conservation efforts? A) Lighting has no impact on energy consumption B) Brighter lighting increases energy efficiency C) Energy-efficient lighting reduces electricity usage D) Dim lighting improves energy conservation
💡Correct Answer: Option C (Energy-efficient lighting reduces electricity usage)
Lighting accounts for a substantial fraction of commercial and domestic electrical energy. Using energy-efficient lighting technologies (such as solid-state LEDs and smart controls) drastically cuts down electrical power demand and carbon emissions.
Q59
Renewable Energy & EnvironmentRenewable Energy & Environment
The solar heater function is to convert the solar energy into: A) Thermal Energy B) Mechanical Energy C) Electrical Energy D) Chemical Energy
💡Correct Answer: Option A (Thermal Energy)
A solar water heater (solar thermal collector) absorbs incoming solar electromagnetic radiation and converts it directly into thermal energy (heat) to warm water or other working fluids.
Q60
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
Which of the following types of draft tubes has the minimum efficiency? A) Elbow draft tube with varying cross-section shape B) Simple elbow draft tube C) Conical draft tube D) Moody spreading draft tube
💡Correct Answer: Option B (Simple elbow draft tube)
Among the common draft tubes, the simple elbow draft tube has the lowest efficiency (about 60%) because of high eddy and flow separation losses at the sharp bend. Conical draft tubes achieve up to 90% efficiency, and Moody spreading draft tubes reach ~85-88%.
Q61
General EnglishGeneral English
Fill in the blank with appropriate word(s): I _______ working all afternoon and have just finished the assignment. A) had been B) have been C) shall be D) am
💡Correct Answer: Option B (have been)
The present perfect continuous tense ('have been working') is required because the action began in the afternoon and continued up to the present moment, directly connected with the present perfect clause 'have just finished'.
Q62
General EnglishGeneral English
Which tense is used to express an action that began in the past before some point and continued up to that point? A) Past indefinite tense B) Past perfect tense C) Past perfect continuous tense D) Past continuous tense
💡Correct Answer: Option C (Past perfect continuous tense)
The Past Perfect Continuous tense (had been + verb-ing) describes an ongoing action that started in the past and continued up to another specified point in the past.
Q63
General EnglishGeneral English
What is the meaning of the idiom "Backstairs Influence"? A) Secret and unfair influence B) Backing Influence C) Political Influence D) Deserving and proper influence
💡Correct Answer: Option A (Secret and unfair influence)
The idiom 'backstairs influence' refers to secret, clandestine, or underhand influence exercised by backdoor or improper methods to gain an undue advantage.
Q64
General EnglishGeneral English
Out of the four alternatives given, choose the one that can best substitute the word: CHIDE A) Prevent B) Rescue C) Follow D) Scold
💡Correct Answer: Option D (Scold)
To 'chide' means to express disapproval or reprimand someone gently or scold them for a fault.
Q65
General EnglishGeneral English
The following sentence has been split into four segments. Identify the segment that contains a grammatical error: Daniel sat on / his new bike / and went afar / a ride. A) Daniel sat on B) his new bike C) and went afar D) a ride
💡Correct Answer: Option C (and went afar)
The segment 'and went afar' is grammatically incorrect in this context. The idiomatic English phrase is 'went for a ride' (or 'went out for a ride'). Using 'went afar a ride' is ungrammatical.
Q66
Computer Science & Information TechnologyComputer Science & IT
Which command in MS-DOS displays only file and directory names without size, date and time information? A) DIR /W B) DIR /A C) DIR /S D) DIR /B
💡Correct Answer: Option D (DIR /B)
In MS-DOS / Windows Command Prompt, the 'DIR /B' command specifies 'bare format', which prints only the bare names of files and directories without heading information, file sizes, timestamps, or summary totals.
Q67
Computer Science & Information TechnologyComputer Science & IT
The Unix operating system is a: A) Time-sharing operating system B) Multi-user operating system C) Multitasking operating system D) All options are correct
💡Correct Answer: Option D (All options are correct)
UNIX is inherently designed from its inception as a multi-user, multitasking, and time-sharing operating system, allowing multiple users to run multiple processes concurrently by time-slicing processor resources.
Q68
Computer Science & Information TechnologyComputer Science & IT
A program that provides a software interface to hardware devices is called? A) Application Software B) Device Driver C) System Software D) All of the above
💡Correct Answer: Option B (Device Driver)
A device driver is a specialized system program that acts as a software abstraction layer and translator between the operating system / applications and specific hardware peripheral devices.
Q69
Computer Science & Information TechnologyComputer Science & IT
Which file format is typically used to save 3D models in 3ds Max? A) .max B) .psd C) .obj D) .dwg
💡Correct Answer: Option A (.max)
The native proprietary scene and 3D model project file format used by Autodesk 3ds Max is '.max'. (.obj is an open geometry exchange format, .psd is Adobe Photoshop, .dwg is AutoCAD).
Q70
Computer Science & Information TechnologyComputer Science & IT
Which of the following is a key application of Computer-Aided Design (CAD) in industrial engineering? A) Product design and visualisation B) Production scheduling C) Manufacturing process simulation D) Material handling system optimisation
💡Correct Answer: Option A (Product design and visualisation)
Computer-Aided Design (CAD) software is primarily utilized to create, modify, analyse, and visualise 2D technical drawings and 3D geometric models of physical parts and products.
Q71
Computer Science & Information TechnologyComputer Science & IT
Which of the following bus structures is usually used to connect I/O devices? A) Single bus B) Multiple bus C) Star bus D) Parallel Bus
💡Correct Answer: Option A (Single bus)
In computer architecture, a single shared system bus (or single bus structure) is commonly used to interconnect the CPU, memory, and common I/O devices due to its simplicity, cost-effectiveness, and standardized modular interface.
Q72
Computer Science & Information TechnologyComputer Science & IT
The first generation computers used _______ for circuitry and _______ for memory. A) Transistor and Magnetic drums B) Vacuum tubes and Magnetic drum C) IC and Magnetic tapes D) IC and solid-state devices
💡Correct Answer: Option B (Vacuum tubes and Magnetic drum)
First-generation computers (1940s-1950s, e.g., ENIAC, UNIVAC I) used vacuum tubes (thermionic valves) for internal circuitry/logic and magnetic drums (or delay lines) for main memory.
Q73
Computer Science & Information TechnologyComputer Science & IT
Which of the following protocols is used for receiving or retrieving emails? A) FTP B) HTTP C) SMTP D) IMAP
💡Correct Answer: Option D (IMAP)
IMAP (Internet Message Access Protocol) and POP3 are standard protocols used by email clients to retrieve and receive messages from a mail server. In contrast, SMTP is used for sending/transmitting outgoing emails.
Q74
Computer Science & Information TechnologyComputer Science & IT
In MS Word, a character that is raised and smaller above the baseline is known as: A) Outlined B) Raised C) Superscript D) Subscript
💡Correct Answer: Option C (Superscript)
A character formatted as superscript is positioned slightly above the normal text baseline and rendered in a smaller font size (e.g., x² or 1st). Subscript is placed below the baseline (e.g., H₂O).
Q75
Computer Science & Information TechnologyComputer Science & IT
Which layer in the OSI model is responsible for managing network connections? A) Network Layer B) Session Layer C) Data Link Layer D) Physical Layer
💡Correct Answer: Option B (Session Layer)
The Session Layer (Layer 5) of the OSI model is responsible for establishing, managing, maintaining, synchronising, and terminating communication sessions and dialogues between applications on networked hosts.
Q76
Computer Science & Information TechnologyComputer Science & IT
You can set the Page Border in MS Excel from: A) From Border tab in Format Cells dialog box B) From Border tool in Formatting toolbar C) From Line Style tool in Drawing toolbar D) You cannot set a page border in Excel
💡Correct Answer: Option D (You cannot set a page border in Excel)
Unlike Microsoft Word which has a dedicated Page Border feature in page layout settings, Microsoft Excel does not have a native page border command. In Excel, you can only format borders around individual cells or cell ranges.
Q77
Computer Science & Information TechnologyComputer Science & IT
To insert a hyperlink in a slide: A) Choose Insert >> Hyperlink B) Press Ctrl + K C) Hyperlinks can't be inserted in slides D) Both (A) & (B)
💡Correct Answer: Option D (Both (A) & (B))
In PowerPoint, a hyperlink can be inserted either via the menu/ribbon by selecting 'Insert > Hyperlink' (or 'Insert > Link') or by using the universal keyboard shortcut Ctrl + K.
Q78
Computer Science & Information TechnologyComputer Science & IT
Which of the following is/are an example of an email service provider? i. Outlook ii. Gmail iii. Yandex A) i and ii B) iii only C) i only D) i, ii and iii
💡Correct Answer: Option D (i, ii and iii)
Microsoft Outlook (outlook.com), Google Gmail, and Yandex Mail are all prominent global email service providers (ESPs).
Q79
Computer Science & Information TechnologyComputer Science & IT
In a web browser, which of the following is responsible for displaying the web pages? A) Server B) Rendering engine C) Cache D) Address Bar
💡Correct Answer: Option B (Rendering engine)
The browser's rendering engine (also known as layout engine, such as Blink, WebKit, or Gecko) is the core software component that parses HTML, CSS, and DOM trees and paints the visual representation of web pages onto the screen.
Q80
Computer Science & Information TechnologyComputer Science & IT
CryptoLocker is an example of which type of malware? A) Ransomware B) Adware C) Spyware D) Worms
💡Correct Answer: Option A (Ransomware)
CryptoLocker is a notorious trojan ransomware that targeted computers running Microsoft Windows. It encrypted victim files using RSA/AES cryptography and demanded a ransom payment (in Bitcoin or prepaid vouchers) to decrypt them.
Which one is not coming under cautionary signs? A) Sharp Curve B) No Parking C) Slippery Road D) Narrow Bridge
💡Correct Answer: Option B (No Parking)
Traffic signs are classified into three types: Regulatory/Mandatory signs (circular), Cautionary/Warning signs (triangular), and Informatory signs (rectangular). 'No Parking' is a mandatory/regulatory sign (prohibitory sign with a red circular border and slash). Sharp Curve, Slippery Road, and Narrow Bridge are cautionary signs.
The erosion between shoulder and pavement leads to: A) Drop B) Break down C) Edge drop D) Flat drop
💡Correct Answer: Option C (Edge drop)
Edge drop (or shoulder drop-off) occurs when the unpaved shoulder erodes or consolidates relative to the paved road surface, resulting in an abrupt vertical elevation difference between the pavement edge and the shoulder.
According to IS classification system, the soils can be classified into: A) 15 groups B) 18 groups C) 03 groups D) 07 groups
💡Correct Answer: Option B (18 groups)
According to the Indian Standard Soil Classification System (IS: 1498 - 1970), soils are classified into 18 distinct groups (8 coarse-grained soil groups: GW, GP, GM, GC, SW, SP, SM, SC; 9 fine-grained soil groups based on 3 plasticity ranges: ML, CL, OL, MI, CI, OI, MH, CH, OH; and 1 highly organic peat group: Pt).
Q84
Mechanical & Civil EngineeringStrength of Materials & Mechanics
The deformation per unit length is called: A) Strain B) Tensile stress C) Compressive stress D) Stress
💡Correct Answer: Option A (Strain)
Strain (ε) is defined as the change in dimension per unit original dimension, specifically change in length divided by original length (ΔL / L), representing deformation per unit length. It is dimensionless.
Q85
Mechanical & Civil EngineeringStrength of Materials & Mechanics
The internal resistance which the body offers to meet the load or external force is called: A) Stress B) Strain C) Pressure D) None of the above
💡Correct Answer: Option A (Stress)
Stress (σ) is defined as the internal resisting force per unit cross-sectional area offered by a deformable material to oppose external applied mechanical loads.
As per third twenty-year road development plan 1981-2001, the urban roads are classified into four categories. Choose the correct order. A) National highways, State highways, Village roads, Other district roads B) Arterial roads, Sub-arterial roads, Collector streets, Local streets C) Primary system, Secondary system, Tertiary system, Village roads D) None of the above
💡Correct Answer: Option B (Arterial roads, Sub-arterial roads, Collector streets, Local streets)
Under the Lucknow Road Plan (Third 20-Year Road Development Plan 1981–2001), urban roads are categorized hierarchically into: (1) Arterial roads, (2) Sub-arterial roads, (3) Collector streets, and (4) Local streets.
Consider the following statements: Statement 1: East Indian Railway company was established by R. M. Stephenson in 1845. Statement 2: In 2008, Kalka-Shimla railway was declared as World Heritage site by UNESCO. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option C (Statement 1 and 2 are correct)
Statement 1 is correct: The East Indian Railway (EIR) Company was established in 1845 by Rowland Macdonald Stephenson. Statement 2 is also correct: The historic Kalka-Shimla narrow-gauge mountain railway was inscribed on the UNESCO World Heritage list in July 2008 as part of the Mountain Railways of India. Thus, both Statement 1 and 2 are correct.
Consider the following statements: Statement 1: The main components of a highway on embankments are: Embankment or fill, Subgrade, Drainage layer, Shoulders, and Pavement layers. Statement 2: Corrugations is longitudinal deformation or depression of the pavement surface along the wheel paths of heavy vehicles. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option A (Statement 1 is correct and Statement 2 is incorrect)
Statement 1 is correct because highway embankment structures comprise the embankment fill, subgrade, subbase/drainage layer, shoulders, and base/surfacing layers. Statement 2 is incorrect because longitudinal depression along the wheel paths is known as 'Rutting'; 'Corrugations' (or washboarding) refer to transverse ripples / wave-like undulations across the pavement surface. Hence, Statement 1 is correct and Statement 2 is incorrect.
Q89
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
Consider the following statements: Statement 1: A reaction turbine is one in which only a part of the potential energy of waste water is converted into purified water and the balance remains as head rate of process. Statement 2: In a Pelton's wheel, the total potential head is changed into kinetic head for affecting the motion of the runner, while in a Francis wheel, only a part of it is converted. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option B (Statement 2 is correct and Statement 1 is incorrect)
Statement 1 is completely false/nonsensical: a hydraulic turbine converts water's potential and pressure energy into mechanical power, not wastewater purification. Statement 2 is technically correct: in a Pelton wheel (impulse turbine), 100% of the available pressure/potential head is converted into kinetic energy via nozzle jets before reaching the runner, whereas in a Francis wheel (reaction turbine), only a fraction is converted into kinetic energy in guide vanes while the remainder exists as pressure head throughout the runner. Hence, Statement 2 is correct and Statement 1 is incorrect.
Q90
Civil & Environmental EngineeringEnvironmental & Water Resources
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I (Type): 1. Surface Source 2. Sub-surface Source 3. Type of precipitation List - II: i. Infiltration galleries ii. Cyclonic iii. Storage reservoirs Choose the correct option: A) (1) - i, (2) - ii, (3) - iii B) (1) - ii, (2) - iii, (3) - i C) (1) - iii, (2) - i, (3) - ii D) (1) - iii, (2) - ii, (3) - i
💡Correct Answer: Option C ((1) - iii, (2) - i, (3) - ii)
1. Surface Source = iii (Storage reservoirs / lakes / rivers); 2. Sub-surface Source = i (Infiltration galleries / wells / springs); 3. Type of precipitation = ii (Cyclonic precipitation / convective / orographic). Thus, the matching code is (1)-iii, (2)-i, (3)-ii.
Q91
Renewable Energy & Hydro PowerHydroelectric & Fluid Power
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I (Turbine): 1. Pelton Turbine 2. Francis Turbine 3. Kaplan and Propeller Turbines List - II (Specific speed in RPM / SI units): i. 10 to 35 ii. 60 to 300 iii. 300 to 1000 Choose the correct option: A) (1) - i, (2) - ii, (3) - iii B) (1) - ii, (2) - iii, (3) - i C) (1) - iii, (2) - i, (3) - ii D) (1) - iii, (2) - ii, (3) - i
💡Correct Answer: Option A ((1) - i, (2) - ii, (3) - iii)
The specific speed (Ns = N√P / H^(5/4) in metric units) ranges for hydraulic turbines are: Pelton turbine (single jet: 10 to 35, multi-jet up to 60); Francis turbine (medium specific speed: 60 to 300); Kaplan and Propeller turbines (high specific speed: 300 to 1000). Thus, 1-i, 2-ii, 3-iii.
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I: 1. Coarse grained components 2. Fine grained components 3. Peat List - II: i. High Organic, Large Organic Matter, Particles of Decomposed Vegetation ii. Boulder, Cobble, Gravel, Sand iii. Silt, Clay, Organic Matter Choose the correct option: A) (1) - i, (2) - ii, (3) - iii B) (1) - ii, (2) - iii, (3) - i C) (1) - iii, (2) - i, (3) - ii D) (1) - ii, (2) - i, (3) - iii
💡Correct Answer: Option B ((1) - ii, (2) - iii, (3) - i)
Coarse grained components include boulders, cobbles, gravel, and sand (size > 0.075 mm) -> (1)-ii. Fine grained components include silt and clay (size < 0.075 mm) along with fine organic matter -> (2)-iii. Peat consists of highly fibrous decayed vegetative organic matter -> (3)-i. Thus, (1)-ii, (2)-iii, (3)-i.
Q93
Mechanical & Civil EngineeringStrength of Materials & Mechanics
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I: 1. Simple Stress 2. Indirect Stress 3. Ratio of lateral strain to linear strain 4. Ratio of linear stress to linear strain List - II: i. Poisson's ratio ii. Torsion iii. Shear iv. Modulus of elasticity Choose the correct option: A) (1) - ii, (2) - iii, (3) - i, (4) - iv B) (1) - ii, (2) - iii, (3) - iv, (4) - i C) (1) - iii, (2) - ii, (3) - iv, (4) - i D) (1) - iii, (2) - ii, (3) - i, (4) - iv
💡Correct Answer: Option D ((1) - iii, (2) - ii, (3) - i, (4) - iv)
1. Simple stress = Shear (direct shear stress) -> (1)-iii; 2. Indirect stress = Torsion (torsional shear produced indirectly by applied twisting moment) -> (2)-ii; 3. Lateral strain / linear strain = Poisson's ratio -> (3)-i; 4. Linear stress / linear strain = Modulus of elasticity (Young's modulus E) -> (4)-iv. Hence, (1)-iii, (2)-ii, (3)-i, (4)-iv.
Q94
Mechanical & Civil EngineeringStrength of Materials & Mechanics
Consider the following statements: Statement 1: In a cantilever with uniformly distributed load, the shearing force varies following a linear law. Statement 2: Bending moment at supports in case of simply supported beams is always zero. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option C (Statement 1 and 2 are correct)
Statement 1 is correct: for a cantilever beam carrying a UDL (w), the shear force V(x) = w * x, which is a linear function of distance x from the free end. Statement 2 is correct: for a simply supported beam with simple hinge/roller end supports, the bending moment at both end supports is identically zero. Thus, both Statement 1 and 2 are correct.
Q95
Mechanical & Civil EngineeringStrength of Materials & Mechanics
In a cantilever, carrying a load whose intensity varies uniformly from zero at the free end to w per unit run at the fixed end, the bending moment changes following a: A) Cubic law B) Parabolic law C) Linear law D) None of the above
💡Correct Answer: Option A (Cubic law)
When load intensity varies linearly (w(x) = wx/L), integrating the load gives the shear force as a parabolic function (V(x) = wx^2 / 2L), and integrating shear gives the bending moment as a cubic function (M(x) = w*x^3 / 6L). Thus, the bending moment changes following a cubic law.
Which of the following forms the basis of rigid bodies and strength of materials? A) The Centroid B) Centre of gravity C) Moment of Inertia D) None of the above
💡Correct Answer: Option C (Moment of Inertia)
Moment of inertia (second moment of area in beam flexure, and mass moment of inertia in rigid body dynamics) is the fundamental geometric and dynamic property governing rotational resistance, flexural stiffness, and structural stability in strength of materials.
_______ is defined as the point where the whole area of the figure is assumed to be concentrated. A) Centroid B) Centre of gravity C) Moment of Inertia D) None of the above
💡Correct Answer: Option A (Centroid)
The Centroid is the geometric centre of a plane figure (2D area) where the total area is assumed to be concentrated. (Centre of gravity applies to mass or weight of 3D bodies).
Q98
Civil & Environmental EngineeringEnvironmental & Water Resources
Consider the following statements: i. The quality of wastewater is determined on the basis of DO. ii. The BOD test is based on DO. iii. Determination of DO helps in controlling corrosion. Which of the above statements are correct? A) i and ii B) ii and iii C) i and iii D) i, ii, and iii
💡Correct Answer: Option D (i, ii, and iii)
All three statements are correct: (i) Dissolved Oxygen (DO) is a critical index for wastewater and natural river health; (ii) The standard BOD (Biochemical Oxygen Demand) test directly measures the depletion of DO over a specified incubation period (BOD = (DO_initial - DO_final) * dilution factor); (iii) Measuring and removing DO in boiler feed water and piping is essential to prevent electrochemical oxygen pitting corrosion.
Q99
Civil & Environmental EngineeringEnvironmental & Water Resources
Standard BOD is measured at: A) 20°C - 3 days B) 20°C - 5 days C) 25°C - 3 days D) 25°C - 5 days
💡Correct Answer: Option B (20°C - 5 days)
Standard Biochemical Oxygen Demand (BOD5) is universally measured by incubating the seeded sample at 20°C for 5 days in an airtight bottle in darkness.
Q100
Civil & Environmental EngineeringEnvironmental & Water Resources
The system to collect night soil, garbage etc. in separate vessels or deposited in pools and pits is called: A) Conservancy system B) Waste allocation system C) Waste deposition system D) Waste pit
💡Correct Answer: Option A (Conservancy system)
The Conservancy system (or dry carriage system) is an old sanitation method where human excreta (night soil), refuse, and garbage are collected manually in vessels, carts, or pits and carried away periodically to disposal sites, without water carriage.
The frictional torque transmitted by a disc or plate clutch is same as that of: A) Flat pivot bearing B) Flat collar bearing C) Conical pivot bearing D) Trapezoidal pivot bearing
💡Correct Answer: Option B (Flat collar bearing)
In a disc or plate clutch, friction contact occurs over an annular ring surface bounded by an inner radius r2 and outer radius r1. This geometry and pressure distribution is identical to that of a flat collar bearing.
The frictional torque transmitted by a cone clutch is same as that of: A) Flat pivot bearing B) Flat collar bearing C) Conical pivot bearing D) Trapezoidal pivot bearing
💡Correct Answer: Option C (Conical pivot bearing)
A cone clutch transmits torque across conical contacting surfaces inclined at semi-cone angle α, which is mathematically identical to the contact geometry and frictional torque equations of a conical pivot bearing (or truncated conical collar).
Q103
Mechanical EngineeringTheory of Machines
When the elements of the pair are kept in contact by the action of external forces, the pair is said to be a: A) Lower pair B) Higher pair C) Self closed pair D) Force closed pair
💡Correct Answer: Option D (Force closed pair)
A kinematic pair in which the contact between two links is maintained by external forces (such as gravity, spring force, or external pressure) rather than by their geometric shape is termed a Force-closed pair (or unclosed pair, e.g., cam and follower without a spring).
Q104
Mechanical EngineeringThermodynamics & Thermal Power
Any transfer of energy to a system by virtue of temperature difference is known as: A) Turbine B) Supply C) Heat D) Moment of Inertia
💡Correct Answer: Option C (Heat)
By thermodynamic definition, Heat (Q) is transient energy in transit across the boundary of a thermodynamic system solely driven by a difference in temperature between the system and its surroundings.
Q105
Mechanical EngineeringRefrigeration & Air Conditioning
_______ reduces the pressure of the refrigerant, and also regulates the flow of the refrigerant to the evaporator. A) Condenser B) Expansion device C) Evaporator D) None of the above
💡Correct Answer: Option B (Expansion device)
The expansion device (such as a capillary tube or thermostatic expansion valve - TXV) performs two essential functions in a vapor compression refrigeration cycle: it drops the high condenser pressure to low evaporator pressure via throttling, and regulates the mass flow rate of refrigerant entering the evaporator.
Q106
Mechanical EngineeringTheory of Machines
Consider the following statements: Statement 1: A flywheel used in machines serves as a reservoir, which stores energy during the period when the supply of energy is more than the requirement, and release it during the period when the requirement of energy is more than the supply. Statement 2: A flywheel controls the speed variations caused by the fluctuation of the engine turning moment during each cycle of operation. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option C (Statement 1 and 2 are correct)
Both statements are correct. A flywheel stores excess kinetic energy during power strokes and supplies it during non-power strokes, thus smoothing out cyclic fluctuations in turning moment and keeping engine angular speed within narrow limits during each operating cycle.
Q107
Mechanical EngineeringTheory of Machines
Consider the following statements: Statement 1: A governor is said to be unstable when for every speed within the working range there is an undefined configuration in equilibrium. Statement 2: A governor is said to hunt if the speed of the engine is constant and maintain 20% above the mean speed. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option D (Statement 1 and 2 are incorrect)
Both statements are incorrect. A governor is unstable if the radius of rotation decreases as the speed increases (or when governor sleeve moves to extreme positions without stabilizing). A governor is said to hunt when it continuously fluctuates/oscillates above and below the mean speed due to excessive sensitivity, not maintaining a constant 20% above mean speed. Thus, both Statement 1 and 2 are incorrect.
Consider the following statements: Statement 1: The efficiency of a screw jack may be defined as the product of ideal effort and the deviations from the actual effort. Statement 2: The collar bearings are also known as thrust bearing. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option B (Statement 2 is correct and Statement 1 is incorrect)
Statement 1 is incorrect: the efficiency of a screw jack is defined as the ratio of ideal effort (P0 without friction) to actual effort (P with friction), η = P0 / P, not a product. Statement 2 is correct: collar bearings support axial loads and are commonly known as thrust bearings. Hence, Statement 2 is correct and Statement 1 is incorrect.
Q109
Mechanical EngineeringTheory of Machines
Consider the following statements: Statement 1: The motion of a piston in the cylinder of a steam engine is an example of completely constrained motion. Statement 2: The cam and follower without a spring forms a self-closed pair. Choose the correct option: A) Statement 1 is correct and Statement 2 is incorrect B) Statement 2 is correct and Statement 1 is incorrect C) Statement 1 and 2 are correct D) Statement 1 and 2 are incorrect
💡Correct Answer: Option A (Statement 1 is correct and Statement 2 is incorrect)
Statement 1 is correct: the motion of a piston in a cylinder is constrained to reciprocate along one definite axis irrespective of the direction of force, making it completely constrained motion. Statement 2 is incorrect: a cam and follower pair is kept in contact by an external force (gravity or spring), so without a spring it is a force-closed pair (unclosed pair), not a self-closed (geometrically closed) pair. Hence, Statement 1 is correct and Statement 2 is incorrect.
Q110
Mechanical EngineeringTheory of Machines
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I: 1. Hartnell Governor 2. To drive a gramophone 3. More sensitive List - II: i. Pickering governor ii. Hunting governor iii. Spring loaded governor Choose the correct option: A) (1) - i, (2) - ii, (3) - iii B) (1) - ii, (2) - iii, (3) - i C) (1) - iii, (2) - i, (3) - ii D) (1) - iii, (2) - ii, (3) - i
💡Correct Answer: Option C ((1) - iii, (2) - i, (3) - ii)
1. Hartnell Governor = iii (Spring loaded centrifugal governor); 2. To drive a gramophone = i (Pickering governor is used for gramophones and small chronometers); 3. More sensitive governor leads to = ii (Hunting governor occurs when a governor is too sensitive). Therefore, the correct match is (1)-iii, (2)-i, (3)-ii.
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I (Terms in Screw): 1. Lead 2. Pitch 3. Helix List - II (Description): i. It is the curve traced by a particle, while describing a circular path at a uniform speed and advancing in the axial direction at a uniform rate. ii. It is the distance from a point of screw to a corresponding point on the next thread, measured parallel to the axis of the screw. iii. It is the distance; a screw thread advances axially in one turn. Choose the correct option: A) (1) - i, (2) - ii, (3) - iii B) (1) - ii, (2) - iii, (3) - i C) (1) - iii, (2) - i, (3) - ii D) (1) - iii, (2) - ii, (3) - i
💡Correct Answer: Option D ((1) - iii, (2) - ii, (3) - i)
1. Lead: Axial advance in one complete revolution = iii; 2. Pitch: Axial distance between corresponding points on adjacent threads = ii; 3. Helix: Space curve generated by a point revolving around a cylinder while advancing linearly = i. Thus, the matching code is (1)-iii, (2)-ii, (3)-i.
Q112
Mechanical EngineeringTheory of Machines
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I (Type of Joints): 1. Ternary Joint 2. Quaternary Joint 3. Binary Joint List - II (Number of links connected): i. 2 links ii. 3 links iii. 4 links Choose the correct option: A) (1) - i, (2) - ii, (3) - iii B) (1) - ii, (2) - iii, (3) - i C) (1) - iii, (2) - i, (3) - ii D) (1) - iii, (2) - ii, (3) - i
💡Correct Answer: Option B ((1) - ii, (2) - iii, (3) - i)
In kinematics of machines: A binary joint connects 2 links -> (3)-i; A ternary joint connects 3 links -> (1)-ii; A quaternary joint connects 4 links -> (2)-iii. Hence, the code is (1)-ii, (2)-iii, (3)-i.
Q113
Mechanical & Civil EngineeringFluid Mechanics
Match List - I with List - II and select the correct answer using the codes given below the lists: List - I (Properties of fluid): 1. Surface tension 2. Viscosity 3. Dynamic Viscosity List - II: i. is a measure of a fluid's resistance to flow ii. also known as absolute viscosity iii. is more relevant in phenomena such as capillary action, droplet formation Choose the correct option: A) (1) - ii, (2) - iii, (3) - i B) (1) - iii, (2) - i, (3) - ii C) (1) - i, (2) - iii, (3) - ii D) (1) - iii, (2) - ii, (3) - i
💡Correct Answer: Option B ((1) - iii, (2) - i, (3) - ii)
1. Surface tension: governs capillary action and droplet formation -> (1)-iii; 2. Viscosity: measure of a fluid's internal friction / resistance to flow -> (2)-i; 3. Dynamic viscosity: also known as absolute viscosity (μ) -> (3)-ii. Hence, (1)-iii, (2)-i, (3)-ii.
Q114
Mechanical & Civil EngineeringFluid Mechanics
Which one of the following laws is applicable to a hydraulic lift? A) Kirchhoff's Law B) Pascal's Law C) Archimedes Law D) None of the above
💡Correct Answer: Option B (Pascal's Law)
Hydraulic lifts, hydraulic presses, and hydraulic brakes operate on Pascal's Law, which states that pressure applied to an enclosed incompressible fluid is transmitted undiminished in all directions throughout the fluid.
What is the number of jaws in self-centred chuck? A) 1 jaw B) 2 jaws C) 3 jaws D) 4 jaws
💡Correct Answer: Option C (3 jaws)
A self-centering lathe chuck (also known as a universal chuck or scroll chuck) typically contains 3 jaws that move radially in unison when turned by a single pinion key, automatically centering cylindrical workpieces.
Choose the correct order of the following metal / minerals as per MOHS hardness scale range from 1 to 10. A) Talc, Calcium, Copper, Cobalt, Diamond B) Talc, Calcium, Diamond, Copper, Cobalt C) Copper, Cobalt, Diamond, Talc, Calcium D) Copper, Cobalt, Diamond, Calcium, Talc
💡Correct Answer: Option A (Talc, Calcium, Copper, Cobalt, Diamond)
On the Mohs hardness scale (1 = softest to 10 = hardest): Talc has hardness 1, Calcium is approximately 1.5, Copper is ~3.0, Cobalt is ~5.0-5.5, and Diamond is 10. Thus, the increasing order of hardness is Talc, Calcium, Copper, Cobalt, Diamond.
_______ is the property of the material that enables it to be drawn out or elongated to an appreciable extent before rupture occurs. A) Flakiness B) Abrasion C) Ductility D) Absorption
💡Correct Answer: Option C (Ductility)
Ductility is the mechanical property of a material enabling it to undergo significant plastic deformation and elongation under tensile stress (such as being drawn into thin wires) before fracturing.
Q118
Mechanical EngineeringAutomobile Engineering
Choose the classification automobiles based on purpose: A) LCV, MCV, HCV B) Passenger vehicle, Goods vehicle, Special vehicle C) Front, Rear, Back wheel base D) Closed, Open, Special Style
💡Correct Answer: Option B (Passenger vehicle, Goods vehicle, Special vehicle)
Automobiles are classified according to purpose/use into: (1) Passenger vehicles (cars, buses), (2) Goods vehicles (trucks, tempos), and (3) Special purpose vehicles (ambulances, fire engines, tankers). (LCV/MCV/HCV is classification by load carrying capacity).
Q119
Mechanical EngineeringThermodynamics & IC Engines
The primary reason for diesel engines having more efficiency than gasoline engines is they: A) Have a longer stroke B) Have a higher compression ratio C) Use a different fuel D) Operate at high temperatures
💡Correct Answer: Option B (Have a higher compression ratio)
Diesel engines operate on the Diesel (or dual) cycle with significantly higher compression ratios (typically 15:1 to 22:1) compared to spark-ignition gasoline engines (typically 8:1 to 12:1 to avoid knocking). Thermodynamic cycle efficiency increases with higher compression ratio, giving diesel engines higher thermal efficiency.
When a bus starts suddenly, the passengers are pushed back. This is example of which of the following? A) Newton's first law B) Newton's second law C) Newton's third law D) None of the above
💡Correct Answer: Option A (Newton's first law)
When a stationary bus suddenly starts moving, the passengers' lower bodies accelerate forward with the bus while their upper bodies tend to stay at rest due to inertia of rest, causing them to fall or feel pushed backwards. This is a classic demonstration of Newton's First Law of Motion (Law of Inertia).
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About JKSSB Technical Officer 2025 Previous Year Paper
This page provides the full solved question paper for the JKSSB Technical Officer examination conducted in 2025. Every MCQ is presented with verified answer keys and detailed bilingual explanations to support concept building.
Key subjects covered in this paper include Electrical Engineering, Electronics & Communication, Computer Science & IT, Renewable Energy & Environment, Renewable Energy & Hydro Power, General English, Computer Science & Information Technology, Civil & Environmental Engineering, Mechanical & Civil Engineering, Mechanical Engineering & Mechanics, Mechanical Engineering. Practicing authentic previous year questions is the proven way to master question patterns and improve accuracy for upcoming exams across Jammu & Kashmir.
