Network Theory Multiple Choice Questions on “Phase Relation in a Pure Resistor”.
1. The phase difference between voltage and current in case of resistor is?
A. in phase
B. out of phase
C. 45⁰ out of phase
D. 90⁰ out of phase
Answer: A
Clarification: The phase difference between voltage and current in case of resistor is in phase. The amplitudes of the waveform may differ according to the value of resistance.
2. In the case of inductor, the voltage?
A. is in phase with the current
B. lags behind the current by 90⁰
C. leads the current by 90⁰
D. is out of phase with the current
Answer: C
Clarification: In the case of inductor, the voltage and current are out of phase. So, the voltage leads the current by 90⁰.
3. For inductor, what is the current?
A. is out of phase with the current
B. leads the current by 90⁰
C. is in phase with the current
D. lags behind the current by 90⁰
Answer: D
Clarification: For inductor, the voltage and current are out of phase. So, the current lags behind the current by 90⁰.
4. The value of inductance reactance is?
A. R
B. ωL
C. 1/ωL
D. ωC
Answer: B
Clarification: The value of inductance reactance is ωL. Hence a pure inductor has an impedance whose value is ωL.
5. The current in the pure capacitor?
A. lags behind the voltage by 90⁰
B. is in phase with the voltage
C. lags behind the voltage by 45⁰
D. leads the voltage by 90⁰
Answer: D
Clarification: In a capacitor, there exists a phase difference between current and voltage. The current in pure capacitor leads the voltage by 90⁰.
6. In case of pure capacitor, the voltage?
A. leads the voltage by 90⁰
B. lags behind the voltage by 45⁰
C. lags behind the voltage by 90⁰
D. is in phase with the voltage
Answer: C
Clarification: In a capacitor, there exists a phase difference between current and voltage. In case of pure capacitor, the voltage lags behind the voltage by 90⁰.
7. The impedance value of a pure capacitor is?
A. ωC
B. 1/ ωC
C. ωL
D. R
Answer: B
Clarification: The impedance value of a pure capacitor is 1/ ωC. And the impedance of the capacitor is called capacitive reactance.
8. One sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. How much is first sine wave shifted in phase from the 0⁰ reference?
A. leads reference angle by 10⁰
B. lags reference angle by 10⁰
C. leads reference angle by 15⁰
D. lags reference angle by 15⁰
Answer: C
Clarification: As first sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. First sine wave leads reference angle by 15⁰ from the 0⁰ reference.
9. One sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. How much is second sine wave shifted in phase from the 0⁰ reference?
A. lags reference angle by 15⁰
B. leads reference angle by 15⁰
C. lags reference angle by 10⁰
D. leads reference angle by 10⁰
Answer: A
Clarification: As first sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. Second sine wave lags reference angle by 15⁰ from the 0⁰ reference.
10. One sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. What is the phase angle between two sine waves?
A. 10⁰
B. 15⁰
C. 20⁰
D. 25⁰
Answer: D
Clarification: As first sine wave has a positive peak at 75⁰, and another has a positive peak at 100⁰. The phase angle between two sine waves mentioned above is 25⁰.