Circuit Theory MCQs
1. What is the unit of conductance?
a) Ohm
b) Siemens
c) Farad
d) Henry
Answer: b) Siemens
2. Kirchhoff’s Current Law (KCL) is based on the law of conservation of:
a) Energy
b) Charge
c) Momentum
d) Mass
Answer: b) Charge
3. Which of the following elements stores energy in the form of a magnetic field?
a) Capacitor
b) Inductor
c) Resistor
d) Diode
Answer: b) Inductor
4. In a series circuit, the same __________ flows through each component.
a) Voltage
b) Current
c) Power
d) Resistance
Answer: b) Current
5. The total resistance in a parallel circuit is:
a) Greater than the largest resistance
b) Equal to the sum of the resistances
c) Less than the smallest resistance
d) Equal to the average of the resistances
Answer: c) Less than the smallest resistance
6. Theveninās theorem states that any linear circuit can be replaced by:
a) A single current source in parallel with a single resistor
b) A single voltage source in series with a single resistor
c) A single voltage source in parallel with a single resistor
d) A single current source in series with a single resistor
Answer: b) A single voltage source in series with a single resistor
7. Norton’s theorem is similar to Thevenin’s theorem, but the circuit is replaced by:
a) A voltage source and series resistance
b) A current source and parallel resistance
c) A voltage source and parallel resistance
d) A current source and series resistance
Answer: b) A current source and parallel resistance
8. In a purely resistive AC circuit, the current is:
a) In phase with the voltage
b) Leading the voltage by 90 degrees
c) Lagging the voltage by 90 degrees
d) Out of phase with the voltage
Answer: a) In phase with the voltage
9. Which of the following is a linear passive element?
a) Transistor
b) Resistor
c) Diode
d) Operational Amplifier
Answer: b) Resistor
10. The superposition theorem is applicable to:
a) Non-linear circuits
b) Linear circuits
c) AC circuits only
d) DC circuits only
Answer: b) Linear circuits
11. A capacitor opposes changes in:
a) Voltage
b) Current
c) Power
d) Resistance
Answer: a) Voltage
12. For maximum power transfer to occur, the load resistance must be:
a) Greater than the source resistance
b) Less than the source resistance
c) Equal to the source resistance
d) Zero
Answer: c) Equal to the source resistance
13. The impedance of an inductor is:
a) Purely resistive
b) Purely capacitive
c) Inductive and resistive
d) Purely inductive
Answer: d) Purely inductive
14. Which of the following devices can be used to step up or step down voltage levels in AC circuits?
a) Transformer
b) Diode
c) Transistor
d) Capacitor
Answer: a) Transformer
15. In a purely capacitive AC circuit, the current:
a) Leads the voltage by 90 degrees
b) Lags the voltage by 90 degrees
c) Is in phase with the voltage
d) Is out of phase with the voltage
Answer: a) Leads the voltage by 90 degrees
16. A resonant circuit is also known as:
a) Band-pass filter
b) Low-pass filter
c) High-pass filter
d) All-pass filter
Answer: a) Band-pass filter
17. The quality factor (Q) of a resonant circuit is a measure of:
a) The bandwidth
b) The sharpness of resonance
c) The impedance
d) The voltage gain
Answer: b) The sharpness of resonance
18. In a parallel RLC circuit at resonance, the current through the inductor and capacitor:
a) Are equal in magnitude and opposite in phase
b) Are equal in magnitude and in phase
c) Are unequal and in phase
d) Are unequal and opposite in phase
Answer: a) Are equal in magnitude and opposite in phase
19. Which of the following is used to convert AC to DC?
a) Rectifier
b) Transformer
c) Oscillator
d) Amplifier
Answer: a) Rectifier
20. In a series RLC circuit, the total impedance at resonance is:
a) Equal to the resistance
b) Equal to the inductive reactance
c) Equal to the capacitive reactance
d) Equal to zero
Answer: a) Equal to the resistance