Explore topic-wise MCQs in Electronics & Communication Engineering.

This section includes 519 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

For the log magnitude Bode plot of the given figure, the transfer function is

A. [A].
B. [B].
C. [C].
D. [D].
Answer» E.
Discussion
52.

A system has two poles as shown in the given figure. The zeros are at infinity. If input is unit step, the steady state output is

A. [A].
B. [B].
C. [C].
D. 1
Answer» E.
Discussion
53.

If , initial and final values of i(t) are

A. zero and 1
B. zero and 10
C. 10 and zero
D. 70 and 80
Answer» D. 70 and 80
Discussion
54.

For the second order system having following differential equation(When θ0 and θi are output and input) the natural frequency is

A. [A].
B. [B].
C. KJ
D. [D].
Answer» B. [B].
Discussion
55.

In the given figure the transfer function

A. [A].
B. [B].
C. [C].
D. [D].
Answer» E.
Discussion
56.

A system with transfer function may be approximated by the system

A. [A].
B. [B].
C. [C].
D. [D].
Answer» B. [B].
Discussion
57.

For the system in the given figure,

A. [A].
B. [B].
C. [C].
D. none of the above
Answer» C. [C].
Discussion
58.

In a two phase ac servomotor rotor resistance is R and rotor reactance is X. The speed curve will be linear if

A. [A].
B. [B].
C. [C].
D. X2 = R
Answer» B. [B].
Discussion
59.

For the system in the given figure, the ratio C(s)/R(s) =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» B. [B].
Discussion
60.

For the mechanical system in the given figure the transfer function =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» B. [B].
Discussion
61.

A feedback amplifier has forward gains A1, A2 and feedback factor β as shown in signal flow graph of the given figure. Because of feedback as shown in signal noise ratio at output will

A. increase
B. decrease
C. be unaffected
D. depend on value of β
Answer» D. depend on value of β
Discussion
62.

In terms of ξ and ωn the settling time (5% criterion) of a second order system for a step input, is equal to

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion
63.

In terms of ξ and ωn the settling time of a second order systems for 2% criterion and step input is equal to

A. [A].
B. [B].
C. [C].
D. [D].
Answer» E.
Discussion
64.

In the given figure shows pole-zero plot. If steady state gain is 2 the transfer function G(s) is

A. [A].
B. [B].
C. [C].
D. [D].
Answer» B. [B].
Discussion
65.

In the given figure the input is x(t) = A sin ωt. The steady state output y(t) =

A. A sin (ωt + φ) where φ = tan-1 |G(jω)|
B. |G(jω)| A sin [ωt + ∠G(jω)]
C. |G(jω)| A sin [2ωt + ∠G(jω)]
D. A G(jω) sin [ωt + ∠G(jω)]
Answer» C. |G(jω)| A sin [2ωt + ∠G(jω)]
Discussion
66.

For the circuit in the given figure,

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion
67.

For the given figure, the transfer function of signal flow graph is

A. [A].
B. [B].
C. [C].
D. [D].
Answer» B. [B].
Discussion
68.

If the characteristic equation is (λ + 1) (λ + 2) (λ + 3) = 0, the eigen values are

A. -1, -2, -3
B. 1, 2, 3
C. 0, 1, 2
D. 0, 2, 3
Answer» B. 1, 2, 3
Discussion
69.

For the system of the given figure |G(jω)| = 0 dB at ω =

A. 0
B. 1 rad/sec.
C. ∞
D. 2.38 rad/sec.
Answer» E.
Discussion
70.

If phase angle of open loop transfer function becomes - 180° at frequency ω1, then gain margin is equal to

A. |G(jω1)|
B. [B].
C. 1 + |G(jω1)|
D. [D].
Answer» C. 1 + |G(jω1)|
Discussion
71.

The polar plot of the given figure is for the term

A. (jω)2
B. 1 + (jω)2
C. [C].
D. [D].
Answer» D. [D].
Discussion
72.

For type 2 system, the magnitude and phase angle of the term (jω)2 in the denominator, at ω = 0, are respectively

A. 0 and - 90°
B. 0 and + 90°
C. infinity and - 180°
D. infinity and + 180°
Answer» D. infinity and + 180°
Discussion
73.

For the transport lag G(jω) = e-jωT, the polar plot is

A. a semi circle
B. a circle
C. a unit circle
D. none of the above
Answer» D. none of the above
Discussion
74.

For the transport lag G(jω) = e-jωT, the phase angle

A. is constant
B. varies linearly with frequency
C. varies linearly with low frequencies only
D. values as per square law
Answer» C. varies linearly with low frequencies only
Discussion
75.

For the transport lag G(jω) = e-jωT, the magnitude is always equal to

A. 0
B. 1
C. 10
D. 0.5
Answer» C. 10
Discussion
76.

The polar plot of G(jω) = 1/jω is

A. positive imaginary axis
B. positive real axis
C. negative imaginary axis
D. negative real axis
Answer» D. negative real axis
Discussion
77.

The open loop transfer function of a system is . If the frequency at the intersection of - 40 dB/decade line and 0 dB line is ω, then

A. [A].
B. [B].
C. [C].
D. [D].
Answer» C. [C].
Discussion
78.

The phase angle curve of G(jω) H(jω) can be drawn

A. by adding the phase angle curves of individual factors
B. by subtracting the phase angle curves of individual factors
C. by multiplying the phase angle curves of individual factors
D. by dividing the phase angle curves of individual factors
Answer» B. by subtracting the phase angle curves of individual factors
Discussion
79.

For a quadratic factor in denominator of transfer function the phase angle at corner frequency (in Bode phase angle plot)

A. is -90°
B. is +90°
C. depends on the damping factor
D. none of the above
Answer» B. is +90°
Discussion
80.

In log magnitude Bode diagram the slope of high frequency asymptote of (1 + jωT) is

A. 20 dB per decade
B. 10 dB per decade
C. 20 dB per octave
D. 10 dB per octave
Answer» B. 10 dB per decade
Discussion
81.

At corner frequency the phase angle of factor 1/(1 + jωT) is

A. +90°
B. -90°
C. +45°
D. -45°
Answer» E.
Discussion
82.

In Bode diagram (log magnitude plot) of the factor 1/(1 + jωT) in the transfer function the log magnitude for ω

A. 0 dB
B. 20 log ωT dB
C. -20 log ωT dB
D. none of the above
Answer» B. 20 log ωT dB
Discussion
83.

In Bode diagram (log magnitude plot) the factor (jω)n in the transfer function gives a line having slope

A. 20 dB/decade
B. 20n dB/decade
C. [C].
D. -20n dB/decade
Answer» C. [C].
Discussion
84.

The damping ratio of a pair of complex poles when expressed in terms of angle θ measured from jω axis equal to

A. sin θ
B. cos θ
C. tan θ
D. cot θ
Answer» B. cos θ
Discussion
85.

For the system of the given figure, the break away and break in points are determined from the conditions . Then K =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» C. [C].
Discussion
86.

For the given figure C(s)/R(s) =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» C. [C].
Discussion
87.

A system has transfer function. If a sinusoidal input of frequency ω is applied the steady state output is of the form

A. [A].
B. K1 K2 (1 + jω/T)
C. K1K2/jωT
D. [D].
Answer» B. K1 K2 (1 + jω/T)
Discussion
88.

For the op-amp circuit of the given figure, Eo(s)/Ei(s) =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» C. [C].
Discussion
89.

For op-amp circuit of the given figure, Eo(s)/Ei(s) =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» E.
Discussion
90.

For the system of given figure the closed loop transfer function

A. [A].
B. [B].
C. [C].
D. [D].
Answer» E.
Discussion
91.

A unity feedback system has open loop transfer function The closed loop transfer function is

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion
92.

In a second order system ωn = 10 rad/sec and ζ = 0.1, then ωd =

A. 9.1 rad/sec
B. 9.95 rad/sec
C. 9 rad/sec
D. 1 rad/sec
Answer» C. 9 rad/sec
Discussion
93.

For the given figure the equation of motion is

A. [A].
B. [B].
C. [C].
D. none of the above
Answer» B. [B].
Discussion
94.

A second order system has damping ratio x and natural frequency ωn. The unit step response is

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion
95.

In the given figure, P = Pm sin ωt. Then X(s) =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» B. [B].
Discussion
96.

In the given figure, P = 3 kg force. Then X(s) =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion
97.

For the given figure, the transfer function X(s)/P(s) =

A. [A].
B. [B].
C. [C].
D. [D].
Answer» C. [C].
Discussion
98.

A motor is coupled to a load through gear ratio n. If T is the motor torque, Jm and JL are moment of inertia of rotor and load, then torque to inertia ratio referred to motor shaft is

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion
99.

For the given figure

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion
100.

The system in the given figure, x(0) = 0 and x (0) = 0, At t = 0 the unit impulse δ(t) is applied X(s)

A. [A].
B. [B].
C. [C].
D. [D].
Answer» D. [D].
Discussion