Question 1
A choke can be electrically modeled as an RL circuit with an ideal inductor in series with a resistor.
TRUE
FALSE
Electrical and Electronic Circuits Quiz 1: 26 October 2025, Set QEF3 (September 2025 term)
The IIT Madras BS Electrical and Electronic Circuits (Electrical and Electronic Circuits) Quiz 1 paper sat on 26 Oct 2025, in the September 2025 term, set QEF3: 22 questions for 35.5 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.
- 22
- 35.5
- 120 min
- 12
- 10
Show answer
Correct answer
TRUE
Question 2
Pure resistive networks have a power factor of zero.
TRUE
FALSE
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Correct answer
FALSE
Question 3
TRUE
FALSE
Show answer
Correct answer
FALSE
Question 4
TRUE
FALSE
Show answer
Correct answer
TRUE
Question 5
Consider a switched capacitor circuit, where the switch abruptly changes from one position (A) to another (B). Assume the transition time is ideally zero. The switching action is best modeled as a step function.
TRUE
FALSE
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Correct answer
TRUE
Question 6
The reactance offered by a capacitor to an alternating current of frequency 50 Hz is 10 Ω. If the frequency is increased to 100 Hz, the reactance becomes
20 Ω
5 Ω
0.5 Ω
0.20 Ω
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Correct answer
5 Ω
Question 7
Consider a series RLC circuit at resonance. Choose the right option.
Statement 1: The current flowing through the circuit is dependent only on the resistance value. Statement 2: The input impedance offered by the circuit is minimum. Statement 3: The voltage across the capacitor can exceed the applied source voltage. Statement 4: The magnitude of the inductive reactance is equal to the capacitive reactance.
Statements 1 and 2 are only true.
Statements 3 and 4 are only true.
Statements 1, 2, and 4 are only true.
All the statements are true.
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Correct answer
All the statements are true.
Question 8
1 V
7 V
5 V
10 V
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Correct answer
5 V
Question 9
2
4
0.02
0.04
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Correct answer
2
Question 10
A load is connected to a network. Across the terminals to which the load is connected, the Thevenin equivalent resistance Rth = 10 Ω and Thevenin equivalent voltage Vth = 20 V. The maximum possible power (in W ) that can be supplied to the load is
5 W
2.5 W
10 W
4 W
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Correct answer
10 W
Question 11
500 VA
866 VA
1000 VA
2000 VA
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Correct answer
2000 VA
Question 12
1 and 2
1 and 4
2 and 3
3 and 4
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Correct answer
1 and 4
Question 13
Based on the above data, answer the given subquestions.
The value of R (in Ω) is _________
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Correct answer: 5
Question 14
Based on the above data, answer the given subquestions.
The value of L ( in H) is _________
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Correct answer: 2.5
Question 15
Based on the above data, answer the given subquestions.
The Thevenin voltage (in V) across A and B is _______
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Correct answer: -6
Question 16
Based on the above data, answer the given subquestions.
The Thevenin resistance (in Ω) between A and B is _________
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Correct answer: -12
Question 17
For an AC circuit, the average power consumed by the circuit is 60 W. The apparent power is 100 VA. The power factor of the circuit is ______
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Correct answer: 0.6
Question 18
The potential difference measured across a coil is 4.5 V when it carries a direct current of 9 A. The same coil, when it carries an alternating current of 9 A at 25 Hz, the potential difference is 24 V. Determine the given subquestions:
The coil resistance in Ω.
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Correct answer: 0.5
Question 19
The potential difference measured across a coil is 4.5 V when it carries a direct current of 9 A. The same coil, when it carries an alternating current of 9 A at 25 Hz, the potential difference is 24 V. Determine the given subquestions:
The value of the choke inductance in mH.
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Correct answer: 16.8 (accepted within ±0.2)
Question 20
The potential difference measured across a coil is 4.5 V when it carries a direct current of 9 A. The same coil, when it carries an alternating current of 9 A at 25 Hz, the potential difference is 24 V. Determine the given subquestions:
Now, if the coil is connected across a 50 V(RMS), 50 Hz supply.
The RMS value of the current (in A) flowing through the coil.
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Correct answer: 9.5
Question 21
The potential difference measured across a coil is 4.5 V when it carries a direct current of 9 A. The same coil, when it carries an alternating current of 9 A at 25 Hz, the potential difference is 24 V. Determine the given subquestions:
Now, if the coil is connected across a 50 V(RMS), 50 Hz supply. The power consumed by the coil (in W)
Show answer
Correct answer: 45.1 (accepted within ±0.1)
Question 22
The potential difference measured across a coil is 4.5 V when it carries a direct current of 9 A. The same coil, when it carries an alternating current of 9 A at 25 Hz, the potential difference is 24 V. Determine the given subquestions:
Now, if the coil is connected across a 50 V(RMS), 50 Hz supply.
The power factor of the circuit.
Show answer
Correct answer: 0.095 (accepted within ±0.005)