289 + Mcqs in Network Elements and the Concept of Circuit Page 1 McqOptions

1.	In the circuit shown below, the values of i(0+) and i( ), will be respectively
A.	0 and 1 5A
B.	1 5A and 3A
C.	3A and 0A
D.	3A and 1 5A
Answer» D. 3A and 1 5A

Discussion

2.	For a two-port network the three parameters A, B and C are given by A = x1, B = x2, C = 1 x2 then D is equal to under the network to be reciprocal
A.	1 x1
B.	0
C.	2 x1
D.	2 x1
Answer» D. 2 x1

Discussion

3.	For the figure given below which of these sets of E, R and C value will ensure that the state equation dVc / dt = 1.25 VC + 2 is valid
A.	2 V, 1 , 1.25 F
B.	1.6 V, 0.8 , 1 F
C.	1.6 V, 1 , 0.8 F
D.	2 V, 1.25 , 1 F
Answer» F.

Discussion

4.	Given T.F. H (s) = s + 2 / s2 + s + 4, under steady state condition, the sinusoidal input and output are respectively x (t) = cos 2t y (t) = cos (2t + ), then angle of will be
A.	45
B.	0
C.	45
D.	90
Answer» D. 90

Discussion

5.	Extra element present in the given circuit
A.	C
B.
C.	C
D.	C
E.	R
Answer» B.

Discussion

6.	The Laplace transform of a function f(t) u(t), where f (t) is periodic with period T, is A(s) times the L.T. of its first period. Then
A.	A(s) = s
B.
C.	A (s) = e
Answer» C. A (s) = e

Discussion

7.	The resonant frequency of the circuit
A.
B.
C.
Answer» B.

Discussion

8.	In the figure the transformer is ideal with adjustable turns ratio N2 / N1 . The turns ratio N2 / N1 for maximum power transfer to the load is
A.	1: 1
B.	100: 1
C.	1: 100
D.	1000: 1
Answer» D. 1000: 1

Discussion

9.	A single phase transformer is connected as shown in fig. when a voltage of 100 V (rms) was applied across AB, the voltmeter connected across AC measured 100 V (rms). The turns ratio N1: N2 is
A.	1: 1
B.	1: 2
C.	2: 1
D.	4: 1
Answer» C. 2: 1

Discussion

10.	Find the value of R so that V2 = 2 volt
A.
B.	2
C.	5
Answer» C. 5

Discussion

11.	Find VC (0+) for the circuit
A.	2 V
B.	2 V
C.	6 V
D.	8 V
Answer» B. 2 V

Discussion

12.	Given iL (0+) = 0, VC (0 ) = 0 in the steady state VC equals to
A.	200 V
B.	100 V
C.	0 V
D.	100 V
Answer» C. 0 V

Discussion

13.	What will be the value of Rth between A and B for the given circuit shown below?
A.	2 R
B.	R
Answer» E.

Discussion

14.	What will be the voltage across the capacitor at t = 0+ for given figure?
A.	2 V
B.	2 V
C.	4 V
D.	1 V
Answer» C. 4 V

Discussion

15.	Switch S in position (1) for long time and moved to position (2) at t = 0 sec. obtain at t = 0+ the value of i L (0+)
A.	3 amp
B.	6 amp
C.	2 amp
D.	5 amp
Answer» B. 6 amp

Discussion

16.	For the networks shown in the figures (a) and (b) to be duals, it is necessary that R , L and C are respectively equal to
A.
B.
Answer» B.

Discussion

17.	The Y11-parameters for the given network shown below are
A.
Answer» B.

Discussion

18.	If L {f (t)} = s2 + 2 , then the value of lim t f (t)
A.	cannot be determined
B.	Zero
C.	1
D.
Answer» B. Zero

Discussion

19.	Switch S in position (a) for a long time and moves to be at t = 0. The value of VC and dVC / dt at t = 0+
A.	12 V, 8 V
B.	12 V, 8 V
C.	4 V, 8 V
D.	4 V, 8 V
Answer» B. 12 V, 8 V

Discussion

20.	A series R-L circuit is initially released. A step voltage is applied to the circuit. If is the time constant of the circuit, the voltage across R and L will be same at time t equal to
A.	log
B.	2
C.
Answer» B. 2

Discussion

21.	In figure shown A1, A2, A3 are ideal ammeters. If A1 and A3 read 5 A and 13 A respectively reading of A2 will be
A.	8 A
B.	12 A
C.	18 A
D.	Indeterminate unless the actual values of R, C and W are specified
Answer» C. 18 A

Discussion

22.	The Resistance RAB in the circuit is
A.	12
B.	10.8
C.	6.75
D.	9
Answer» E.

Discussion

23.	In a series RLC circuit excited by a voltage V (t) = A sin t where 2 < 1
A.	a current lags the excitation voltage.
B.	the excitation voltage lags the current.
C.	the voltage across the inductor is < the voltage across the capacitor.
D.	the voltage across the inductor is > the voltage across the capacitor.
Answer» C. the voltage across the inductor is < the voltage across the capacitor.

Discussion

24.	The transform of the square wave can be represented as
A.
B.
Answer» C.

Discussion

25.	System function H (s) =1, for a signal cos t, the steady state response is s + 1
A.
B.
Answer» C.

Discussion

26.	The Laplace transform of the sawtooth waveform is
A.
B.
C.
Answer» B.

Discussion

27.	The voltage of the source i.e. Vs, if i (t) = 20 e 2t
A.	10 e
B.
C.	10 e
D.	20 e
E.	20 e
Answer» B.

Discussion

28.	The Laplace transform of the function f (t) = et2 4t will be
A.	does not exist
Answer» E.

Discussion

29.	The capacitor C1 in the circuit shown has a voltage of 20 V across it before the switch S is closed at time t = 0. C1 = 2 F and C2 = 3 F. The voltage across C2 after S is closed is
A.	8 V
B.	10 V
C.	12 V
D.	15 V
Answer» B. 10 V

Discussion

30.	For fig. at time t 0 after the switch K was closed, it is found that V2 = + 5 V, determine the value of i 2 (t 0) and d / dt i2 (t 0)
A.	2.5 amp, 5 amp/sec
B.	2.5 amp, 2.5 amp/sec
C.	5 amp, 2.5 amp/sec
D.	5 amp, 5 amp/sec
Answer» B. 2.5 amp, 2.5 amp/sec

Discussion

31.	The Thevenin equivalent voltage Vm appearing between the terminals A and B of the network shown is given by
A.	J 16 (3 J 4)
B.	J 16 (J 3 + 4)
C.	J 6 (3 + J 4)
D.	J 6 (3 J 4)
Answer» C. J 6 (3 + J 4)

Discussion

32.	The circuit shown in the figure is in steady state, when the switch is closed at t = 0. Assuming that the inductance is ideal, the current through the inductor at t = 0+ equals
A.	0A
B.	0 5 A
C.	1A
D.	2A
Answer» D. 2A

Discussion

33.	If, at t = 0+, the voltage across the coil is 120V, the value of resistance R is
A.	0
B.	20
C.	40
D.	60
Answer» B. 20

Discussion

34.	For the circuit shown in figure, the voltage Vs will be
A.	12 V
B.	8 V
C.	4 V
D.	13 V
Answer» E.

Discussion

35.	In the circuit shown in figure, the switch S is closed at time t = 0. The voltage across the inductance at t = 0+, is
A.	2V
B.	4V
C.	6 V
D.	8V
Answer» C. 6 V

Discussion

36.	In fig. (a) the values i L, Vc as shown have initial values i L (0 ) = 1 and Vc (0 ) = 2 fig. (b) is the equivalent circuit in the s-domain. The values of V1 and V2 are
A.
B.
C.	1 and 2
Answer» C. 1 and 2

Discussion

37.	The voltage marked Vx is given by
A.	None of these.
Answer» C.

Discussion

38.	In the circuit V2 = 2 V and I1 = 2 amp. The value of Is is given by
A.	2
B.	4
C.	5
D.	6
Answer» C. 5

Discussion

39.	For the given graph, match List I with List II List I List IIA.1, 2, 3, 4 1. Twigs B.4, 5, 6, 72. Links C.1, 2, 3, 4 3. Fundamental cutset D. 1, 4, 5, 6, 7 4.Fundamental loop
A.	3 1 2 4
B.	2 3 1 4
C.	3 2 1 4
D.	1 2 3 4
Answer» B. 2 3 1 4

Discussion

40.	The dimension of LC is
A.	zero
B.
C.	(second)
D.
E.	(second)
Answer» E. (second)

Discussion

41.	The Laplace transform of (t 2 2t) u (t 1) is
A.	None of these
Answer» E.

Discussion

42.	For the circuit shown below in the figure, the voltage V0 is
A.	2 V
B.	1 V
C.	1 V
D.	None of these
Answer» E.

Discussion

43.	The natural frequency Sn of the given circuit is
A.	1
B.	-1
C.	2
Answer» C. 2

Discussion

44.	Given V2 = 1 e 2t, the value of V1 is given by
A.	3 + e
B.	1 + 3 e
C.	4 + 2 e
D.	4
Answer» E.

Discussion

45.	In the circuit of the given figure, the magnitude of VL and VC are twice that of VR. The inductance of the coil is
A.	2.14 mH
B.	5.30 H
C.	31.8 mH
D.	1.32 H
Answer» D. 1.32 H

Discussion

46.	Initial voltage on capacitor V0 as marked \| V0 \| = 5 V. Vs = 8 u(t), where u(t) is the unit step. The voltage marked V at t = 0+ is given by
A.	1 V
B.	1 V
Answer» D.

Discussion

47.	A voltage waveform V (t) = 12 t 2 is applied across 1 H inductor for t 0, with initial current through it being zero the current through the inductor for t 0 is given by
A.	12 t
B.	24 t
C.	12 t
D.	4 t
Answer» E.

Discussion

48.	In the circuit Vs = cos 2t. The value of C is chosen so that I from Vs is in phase with Vs. Then Ic leads IL by an angle given by
A.	45
B.	90
C.	135
D.	0
Answer» D. 0

Discussion

49.	S is in position (a) for a long time. S moved to position (b) at t = 0 , At t = 0+, the values of IC and VL are
A.	5, 0
B.	5, 0
C.	0, 4
D.	2, 3
Answer» B. 5, 0

Discussion

50.	A source Vs = 200 cos t delivers power to a load at power factor 0.8 lagging. The reactive power is 300 VAR. The Pav is given by
A.	200 watts
B.	225 watts
C.	400 watts
D.	300 watts
Answer» D. 300 watts

Discussion

Explore topic-wise MCQs in Network Theory.

In the circuit shown below, the values of i(0+) and i( ), will be respectively

For a two-port network the three parameters A, B and C are given by A = x1, B = x2, C = 1 x2 then D is equal to under the network to be reciprocal

For the figure given below which of these sets of E, R and C value will ensure that the state equation dVc / dt = 1.25 VC + 2 is valid

Given T.F. H (s) = s + 2 / s2 + s + 4, under steady state condition, the sinusoidal input and output are respectively x (t) = cos 2t y (t) = cos (2t + ), then angle of will be

Extra element present in the given circuit

The Laplace transform of a function f(t) u(t), where f (t) is periodic with period T, is A(s) times the L.T. of its first period. Then

The resonant frequency of the circuit

In the figure the transformer is ideal with adjustable turns ratio N2 / N1 . The turns ratio N2 / N1 for maximum power transfer to the load is

A single phase transformer is connected as shown in fig. when a voltage of 100 V (rms) was applied across AB, the voltmeter connected across AC measured 100 V (rms). The turns ratio N1: N2 is

Find the value of R so that V2 = 2 volt

Find VC (0+) for the circuit

Given iL (0+) = 0, VC (0 ) = 0 in the steady state VC equals to

What will be the value of Rth between A and B for the given circuit shown below?

What will be the voltage across the capacitor at t = 0+ for given figure?

Switch S in position (1) for long time and moved to position (2) at t = 0 sec. obtain at t = 0+ the value of i L (0+)

For the networks shown in the figures (a) and (b) to be duals, it is necessary that R , L and C are respectively equal to

The Y11-parameters for the given network shown below are

If L {f (t)} = s2 + 2 , then the value of lim t f (t)

Switch S in position (a) for a long time and moves to be at t = 0. The value of VC and dVC / dt at t = 0+

A series R-L circuit is initially released. A step voltage is applied to the circuit. If is the time constant of the circuit, the voltage across R and L will be same at time t equal to

In figure shown A1, A2, A3 are ideal ammeters. If A1 and A3 read 5 A and 13 A respectively reading of A2 will be

The Resistance RAB in the circuit is

In a series RLC circuit excited by a voltage V (t) = A sin t where 2 < 1

The transform of the square wave can be represented as

System function H (s) =1, for a signal cos t, the steady state response is s + 1

The Laplace transform of the sawtooth waveform is

The voltage of the source i.e. Vs, if i (t) = 20 e 2t

The Laplace transform of the function f (t) = et2 4t will be

The capacitor C1 in the circuit shown has a voltage of 20 V across it before the switch S is closed at time t = 0. C1 = 2 F and C2 = 3 F. The voltage across C2 after S is closed is

For fig. at time t 0 after the switch K was closed, it is found that V2 = + 5 V, determine the value of i 2 (t 0) and d / dt i2 (t 0)

The Thevenin equivalent voltage Vm appearing between the terminals A and B of the network shown is given by

The circuit shown in the figure is in steady state, when the switch is closed at t = 0. Assuming that the inductance is ideal, the current through the inductor at t = 0+ equals

If, at t = 0+, the voltage across the coil is 120V, the value of resistance R is

For the circuit shown in figure, the voltage Vs will be

In the circuit shown in figure, the switch S is closed at time t = 0. The voltage across the inductance at t = 0+, is

In fig. (a) the values i L, Vc as shown have initial values i L (0 ) = 1 and Vc (0 ) = 2 fig. (b) is the equivalent circuit in the s-domain. The values of V1 and V2 are

The voltage marked Vx is given by

In the circuit V2 = 2 V and I1 = 2 amp. The value of Is is given by

For the given graph, match List I with List II List I List IIA.1, 2, 3, 4 1. Twigs B.4, 5, 6, 72. Links C.1, 2, 3, 4 3. Fundamental cutset D. 1, 4, 5, 6, 7 4.Fundamental loop

The dimension of LC is

The Laplace transform of (t 2 2t) u (t 1) is

For the circuit shown below in the figure, the voltage V0 is

The natural frequency Sn of the given circuit is

Given V2 = 1 e 2t, the value of V1 is given by

In the circuit of the given figure, the magnitude of VL and VC are twice that of VR. The inductance of the coil is

Initial voltage on capacitor V0 as marked | V0 | = 5 V. Vs = 8 u(t), where u(t) is the unit step. The voltage marked V at t = 0+ is given by

A voltage waveform V (t) = 12 t 2 is applied across 1 H inductor for t 0, with initial current through it being zero the current through the inductor for t 0 is given by

In the circuit Vs = cos 2t. The value of C is chosen so that I from Vs is in phase with Vs. Then Ic leads IL by an angle given by

S is in position (a) for a long time. S moved to position (b) at t = 0 , At t = 0+, the values of IC and VL are

A source Vs = 200 cos t delivers power to a load at power factor 0.8 lagging. The reactive power is 300 VAR. The Pav is given by