Practice Test: Question Set - 02
1. The power is measured in terms of decibels in case of
- (A) Electronic equipment
- (B) Transformers
- (C) Current transformers
- (D) Auto transformers
2. Wire-wound resistors are unsuitable for use at high frequencies because they
- (A) Create more electrical noise
- (B) Are likely to melt under excessive eddy
current heat
- (C) Consume more power
- (D) Exhibit unwanted inductive and capacitive effects
3. The product of apparent power and cosine of the phase angle between circuit voltage and current is
- (A) True power
- (B) Reactive power
- (C) Volt-amperes
- (D) Instantaneous power
4. In a series resonant circuit, the impedance of the circuit is
- (A) Minimum
- (B) Maximum
- (C) Zero
- (D) None of the above
5. In series resonant circuit, increasing inductance to its twice value and reducing capacitance to its half value
- (A) Will change the maximum value of current at
resonance
- (B) Will change the resonance frequency
- (C) Will change the impedance at resonance
frequency
- (D) Will increase the selectivity of the circuit
6. In a loss-free R-L-C circuit the transient current is
- (A) Oscillating
- (B) Square wave
- (C) Sinusoidal
- (D) Non-oscillating
7. In a circuit containing R, L and C, power loss can take place in
- (A) C only
- (B) L only
- (C) R only
- (D) All above
8. Time constant of a capacitive circuit
- (A) Increases with the decrease of capacitance and
decrease of resistance
- (B) Increases with the decrease of capacitance and
increase of resistance
- (C) Increases with the increase of capacitance and
decrease of resistance
- (D) Increase with increase of capacitance and
increase of resistance
9. The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of
- (A) Iron loss in core
- (B) Skin effect
- (C) Increase in temperature
- (D) Capacitive effect between adjacent coil turns
10. Skin effect occurs when a conductor carries current at _________ frequencies.
- (A) Very low
- (B) Low
- (C) Medium
- (D) High
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