Practice Test: Question Set - 07
1. A pure capacitor connected across an A.C. voltage consumed 50 W. This is due to
- (A) The capacitive reactance in ohms
- (B) The current flowing in capacitor
- (C) The size of the capacitor being quite big
- (D) The statement is incorrect
2. The period of a wave is
- (A) The same as frequency
- (B) Time required to complete one cycle
- (C) Expressed in amperes
- (D) None of the above
3. The r.m.s. value and mean value is the same in the case of
- (A) Triangular wave
- (B) Sine wave
- (C) Square wave
- (D) Half wave rectified sine wave
4. Poor power factor
- (A) Reduces load handling capability of
electrical system
- (B) Results in more power losses in the
electrical system
- (C) Overloads alternators, transformers and distribution
lines
- (D) Results in all above
5. Power factor of the system is kept high
- (A) To reduce line losses
- (B) To maximize the utilization of the capacities of
generators, lines and transformers
- (C) To reduce voltage regulation of the line
- (D) Due to all above reasons
6. Inductance of coil
- (A) Is unaffected by the supply frequency
- (B) Decreases with the increase in supply
frequency
- (C) Increases with the increase in supply
frequency
- (D) Becomes zero with the increase in supply
frequency
7. Which of the following coil will have large resonant frequency?
- (A) A coil with large resistance
- (B) A coil with low resistance
- (C) A coil with large distributed capacitance
- (D) A coil with low distributed capacitance
8. At very low frequencies a series R-C circuit behaves as almost purely
- (A) Resistive
- (B) Inductive
- (C) Capacitive
- (D) None of the above
9. The phosphors for which of the following pair are 180° out of phase for VL, VC and VR?
- (A) VC and VR
- (B) VL and VR
- (C) VC and VL
- (D) None of the above
10. The period of a sine wave is _________ seconds. Its frequency is
- (A) 20 Hz
- (B) 30 Hz
- (C) 40 Hz
- (D) 50 Hz
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