Explore topic-wise MCQs in Electric Circuits.

This section includes 72 Mcqs, each offering curated multiple-choice questions to sharpen your Electric Circuits knowledge and support exam preparation. Choose a topic below to get started.

51.

A coil of 300 turns is wound on a non-magnetic core having a mean circumference of 300 mm and a cross-sectional area of 300 mm

A. 37.68 H
B. 113.04 H
C. 37.68 mH
D. 113.04 mH
Answer» C. 37.68 mH
Discussion
52.

An energy meter connected to an immersion heater (resistive) operating on an AC 230 V, 50 H z, AC single phase source reads 2.3 units (kWh) in 1 hour. The heater is removed from the supply and now connected to a 400 V peak to peak square wave source of 150 Hz. The power in kW dissipated by the heater will be

A. 3.478
B. 1.739
C. 1.540
D. 0.870
Answer» C. 1.540
Discussion
53.

An incandescent lamp is marked 40W, 240V. If resistance at room temperature (26 C) is 120 Ω and temperature coefficient of resistance is 4.5 10

A. 1171
B. 2471
C. 1417
D. All of the above
Answer» C. 1417
Discussion
54.

Consider the following statements with reference to the equation p t

A. Only 2 and 4 are true
B. 1, 2 and 3 are true
C. 2, 3 and 4 are true
D. 1, 2 and 4 are true
Answer» E.
Discussion
55.

Two identical coupled inductors are connected in series. The measured inductances for the two possible series connections are 380 H and 240 H. Their mutual inductance in H is _____

A. 35 to 35
B. 36
C. 35
D. 30 to 35
Answer» B. 36
Discussion
56.

Two identical coils each having inductance L are placed together on the same core. If an over all inductance of L is obtained by interconnecting these two coils, the minimum value of is ______.

A. 10
B. 0.1
C. 0
D. 10
Answer» D. 10
Discussion
57.

In a linear two-port network, when 10 V is applied to Port 1, a current of 4 A flows through Port 2 when it is short-circuited. When 5V is applied to Port 1, a current of 1.25 A flows through a 1Ω resistance connected across Port 2. When 3V is applied to Port 1, then current (in Ampere) through a 2 Ω resistance connect ed acoss Port 2 is _________.

A. 0.545
B. 45
C. 54
D. 545
Answer» B. 45
Discussion
58.

Which of the following statements holds for the divergence of electric and magnetic flux densities?

A. Both are zero
B. These are zero for static densities but non zero for time varying densities
C. It is zero for the electric flux density
D. It is zero for the magnetic flux density
Answer» E.
Discussion
59.

A capacitor consists of two metal plates each 500 500 mm

A. 983.33 pF
B. 1475 pF
C. 6637.5 pF
D. 9956.25 pF
Answer» C. 6637.5 pF
Discussion
60.

Divergence of the three-dimensional radial vector field

A. 3
B. 1 / r
C. <img src="http://images.interviewmania.com/wp-content/uploads/2019/11/as-773.jpg">
D. <img src="http://images.interviewmania.com/wp-content/uploads/2019/11/as-774.jpg">
Answer» B. 1 / r
Discussion
61.

A series R-L-C circuit has R = 50 &ohm; , L = 100 F and C = 1 F. The lower half power frequency of the circuit is _________ kHz

A. 3.055 k Hz.
B. 1.01 k Hz.
C. 14.054 k Hz.
D. None of the above
Answer» B. 1.01 k Hz.
Discussion
62.

A series LCR circuit consisting of R = 10 ohms [X

A. 200 90 V
B. 200 + 90 V
C. 400 + 90 V
D. 400 90 V
Answer» E.
Discussion
63.

The driving-point impedance of a one-port reactive network is given by

A. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>(s<sup>2</sup> + 1)(s<sup>2</sup> + 2)</center></td><td rowspan="2"></td></tr><tr><td style="text-align: center;">s (s<sup>2</sup> + 3) (s<sup>2</sup> + 4)</td></tr></table>
B. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>(s<sup>2</sup> + 1)(s<sup>2</sup> + 3)</center></td><td rowspan="2"></td></tr><tr><td style="text-align: center;">s (s<sup>2</sup> + 2) (s<sup>2</sup> + 4)</td></tr></table>
C. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s<sup>2</sup> (s<sup>2</sup> + 1)</center></td><td rowspan="2"></td></tr><tr><td style="text-align: center;">(s<sup>2</sup> + 2) (s<sup>2</sup> + 3)</td></tr></table>
D. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>1</center></td><td rowspan="2"></td></tr><tr><td style="text-align: center;">s + 1</td></tr></table>
Answer» C. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s<sup>2</sup> (s<sup>2</sup> + 1)</center></td><td rowspan="2"></td></tr><tr><td style="text-align: center;">(s<sup>2</sup> + 2) (s<sup>2</sup> + 3)</td></tr></table>
Discussion
64.

For a 2-port symmetrical bilateral network, if transmission parameters A = 3 and B = 1 &ohm;, then value of parameter C is

A. 3 &ohm;
B. 8 &ohm;
C. 8 &ohm;
D. 9 &ohm;
Answer» C. 8 &ohm;
Discussion
65.

A battery charger can drive a current of 5 A into a 1 ohm resistance connected at its output teminals. If it is able to charge an ideal 2 V battery at 7 A rate, then its Thevenin s equivalent will be

A. 7.5 V in series with 0.5 ohm
B. 12 V in series with 1.5 ohms
C. 7.5 V in parallel with 0.5 ohm
D. 1.25 V in parallel with 1.5 ohms
Answer» C. 7.5 V in parallel with 0.5 ohm
Discussion
66.

A resistor R is connected to a voltage source V

A. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>V<sub>s</sub> R<sub>s</sub> R<sub>m</sub></center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">R<sub>s</sub> R<sub>m</sub> + R<sub>s</sub> R + R R<sub>m</sub></td></tr></table>
B. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>V<sub>s</sub> R</center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">R + R<sub>s</sub> </td></tr></table>
C. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>V<sub>s</sub> R<sub>m</sub></center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">R R<sub>s</sub> + R<sub>m</sub></td></tr></table>
D. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>V<sub>s</sub> R R<sub>m</sub></center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">R<sub>s</sub> R + R<sub>s</sub> R<sub>m</sub> + R R<sub>m</sub></td></tr></table>
Answer» E.
Discussion
67.

A balanced star-connected load with impedance of 20 300 ohm is supplied from a 3-phase, 4-wire, 173 volts system, the voltages to neutral being 100 900, 100 300 and 100 1500 V. The current in the neutral wire is _______ A

A. 1
B. 2
C. 3
D. None of the above
Answer» E.
Discussion
68.

A series RLC circuit s observed at two frequencies. At

A. R = 50 &ohm; ; L = 25mH ; C =10 F;
B. R = 50 &ohm; ; L =10mH ; C = 25 F;
C. R = 50 &ohm; ; L = 50mH ; C = 5 F;
D. R = 50 &ohm; ; L = 5mH ; C = 50 F;
Answer» C. R = 50 &ohm; ; L = 50mH ; C = 5 F;
Discussion
69.

In an unbalanced three phase system, phase current I

A. 1.00
B. 7.81
C. 11.53
D. 13.00
Answer» D. 13.00
Discussion
70.

Consider a function f = 1r , where r is distance from origin and r is unit vector. r2

A. 0
B. 2
C. 4
D. R .
Answer» D. R .
Discussion
71.

A ramp voltage v(t) = 100 volts, is applied to an RC differentiating circuit with R = 5 k &ohm; and C = 4 F. The maximum output voltage is _______V

A. 0
B. 1
C. 2
D. 3
Answer» D. 3
Discussion
72.

In a two-terminal network, open-circuit voltage mesured at the given terminals by an electronic vol t met er is 100 V. A short -circuit current measured at the same terminals by an ammeter of negligible resistance is 5 A. If a load resistor of 80 &ohm; is connected at the same terminals, then current in the load resistor will be ________ A

A. 1
B. 2
C. 3
D. 4
Answer» B. 2
Discussion