For a passive linear network, the input impedance looking into terminals is Z(s). If a unit impulse is applied as input, the impulse response h(t) is the:

The correct answer is C: Inverse Laplace transform of Y(s) where Y(s) = 1/Z(s). Impulse response h(t) = L⁻¹[Y(s)] where Y(s) is admittance. For impedance Z(s), admittance Y(s) = 1/Z(s).

The sensitivity function S(s) in a feedback control system is defined as:

The correct answer is B: S(s) = 1/[1+G(s)H(s)]. Sensitivity S(s) = ∂Y/∂G ÷ Y/G = 1/[1+G(s)H(s)] for unity feedback systems. It measures effect of parameter variations.

What is the effect of increasing system frequency above nominal value in a power system?

The correct answer is C: Increases inductive reactance (X = 2πfL) and reduces capacitive reactance. Since inductive reactance X_L = 2πfL and capacitive reactance X_C = 1/(2πfC), increasing frequency increases X_L and decreases X_C.

Which bridge circuit is specifically designed to measure inductance with small resistance?

The correct answer is A: Maxwell bridge. Maxwell bridge is used for measuring inductance (especially with small resistance) in industrial and laboratory applications.

What is the minimum number of NAND gates required to implement a NOT gate?

The correct answer is A: 1 NAND gate. A single NAND gate with both inputs tied together acts as a NOT gate (inverter).

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Electrical Engg (EEE)

Electrical machines, power systems, circuits

321 Q 7 Topics Take Mock Test

Difficulty: All Easy Medium Hard 311–320 of 321

Topics in Electrical Engg (EEE)

All Circuit Analysis 100 Electrical Machines 100 Power Systems 100 Control Systems 100 Power Electronics 100 Electrical Measurements 40 Digital Electronics 100

Q.311 Medium Circuit Analysis

In Norton's theorem, the Norton equivalent current (IN) is found by:

A Short-circuiting the load terminals and calculating the current through the short circuit

B Open-circuiting the load terminals

C Removing all independent sources

D Calculating Thévenin voltage divided by Thévenin resistance

Correct Answer: A. Short-circuiting the load terminals and calculating the current through the short circuit

EXPLANATION

Norton current is the short-circuit current at the load terminals. IN = VTh/RTh.

Test

Q.312 Medium Circuit Analysis

The equivalent resistance of two resistors in parallel is always:

A Less than the smaller resistor

B Greater than both resistors

C Equal to their arithmetic mean

D Equal to their sum divided by 2

Correct Answer: A. Less than the smaller resistor

EXPLANATION

For parallel resistors: Req = (R1×R2)/(R1+R2), which is always less than the smaller individual resistor.

Test

Q.313 Medium Circuit Analysis

In a series RLC circuit at resonance, the impedance is:

A Minimum and equal to R

B Maximum and equal to R

C Equal to XL + XC

D Equal to √(R² + L²)

Correct Answer: A. Minimum and equal to R

EXPLANATION

At resonance, XL = XC, so they cancel. Z = R (minimum), and current is maximum.

Test

Q.314 Medium Circuit Analysis

In a delta-wye (Δ-Y) conversion, if the delta resistances are RA, RB, RC, the wye resistance R1 (between node 1 and star point) is:

A (RA×RB)/(RA+RB+RC)

B RA+RB+RC

C (RA×RC)/(RA+RB+RC)

D RA/3

Correct Answer: A. (RA×RB)/(RA+RB+RC)

EXPLANATION

In Δ-Y conversion, each Y-resistor equals the product of adjacent Δ-resistors divided by the sum of all Δ-resistors.

Test

Q.315 Medium Circuit Analysis

The bandwidth of a resonant circuit is related to Q-factor by:

A BW = f₀/Q

B BW = Q/f₀

C BW = Q×f₀

D BW = f₀²/Q

Correct Answer: A. BW = f₀/Q

EXPLANATION

Bandwidth is inversely proportional to Q-factor. Higher Q means narrower bandwidth. BW = f₀/Q.

Test

Q.316 Medium Circuit Analysis

A bridge circuit is balanced when:

A Z1×Z3 = Z2×Z4

B Z1+Z2 = Z3+Z4

C Z1/Z2 = Z3/Z4

D Z1-Z2 = Z3-Z4

Correct Answer: A. Z1×Z3 = Z2×Z4

EXPLANATION

For a balanced AC bridge, the product of opposite arm impedances must be equal: Z1×Z3 = Z2×Z4.

Test

Q.317 Medium Circuit Analysis

A capacitor and inductor are in series with resonance occurring at 100 Hz. If L = 25 mH, the capacitance C is approximately:

A 101.3 µF

B 50.65 µF

C 202.6 µF

D 25.3 µF

Correct Answer: A. 101.3 µF

EXPLANATION

At resonance: f = 1/(2π√LC). C = 1/(4π²f²L) = 1/(4π²×10000×0.025) ≈ 101.3 µF.

Test

Q.318 Medium Circuit Analysis

In Thevenin's theorem, the Thevenin equivalent voltage (VTh) is found by:

A Open-circuiting the load and measuring voltage across its terminals

B Short-circuiting the load and measuring current

C Applying a test voltage at the terminals

D Calculating the average voltage across all elements

Correct Answer: A. Open-circuiting the load and measuring voltage across its terminals

EXPLANATION

Thevenin voltage is the open-circuit voltage measured across the load terminals after removing the load.

Test

Q.319 Medium Circuit Analysis

The Q-factor (quality factor) of a resonant circuit is defined as:

A Q = (1/R)√(L/C)

B Q = R√(L/C)

C Q = ω₀L/R or 1/(ω₀RC)

D Q = R/(ω₀L)

Correct Answer: C. Q = ω₀L/R or 1/(ω₀RC)

EXPLANATION

Q-factor represents selectivity and bandwidth characteristics. For series RLC: Q = ω₀L/R = 1/(ω₀RC) = (1/R)√(L/C).

Test

Q.320 Medium Circuit Analysis

In a parallel RC circuit, the total admittance Y is given by:

A Y = G + jωC where G = 1/R

B Y = G - jωC

C Y = √(G² + ω²C²)

D Y = G/(1 + ωC)

Correct Answer: A. Y = G + jωC where G = 1/R

EXPLANATION

In a parallel RC circuit, admittances add directly. Y = G + jBC where G = 1/R and BC = ωC.

Test

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