Practice Test: Question Set - 08
1. For the same peak value, which of the following wave has the least mean value?
- (A) Half wave rectified sine wave
- (B) Triangular wave
- (C) Sine wave
- (D) Square wave
2. The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that
- (A) Both waves must have same frequency
- (B) Both waves must have identical peak values
- (C) Both waves must have zero value at the same
time
- (D) None of the above
3. The square waveform of current has following relation between r.m.s. value and average value.
- (A) r.m.s. value is equal to average value
- (B) r.m.s. value of current is greater than
average value
- (C) r.m.s. value of current is less than average
value
- (D) None of the above
4. Time constant of an inductive circuit
- (A) Increases with increase of inductance and decrease
of resistance
- (B) Increases with the increase of inductance and the
increase of resistance
- (C) Increases with the decrease of inductance and
decrease of resistance
- (D) Increases with decrease of inductance and increase
of resistance
5. In AC. circuits, laminated iron is invariably used in order to
- (A) Reduce eddy current loss
- (B) Increase heat radiation
- (C) Make assembly cheap and easier
- (D) Reduce circuit permeability
6. At __________ frequencies the parallel R-L circuit behaves as purely resistive.
- (A) Low
- (B) Very low
- (C) High
- (D) Very high
7. When an alternating current passes through an ohmic resistance the electrical power converted into heat is
- (A) Apparent power
- (B) True power
- (C) Reactive power
- (D) None of the above
8. Power factor of an electrical circuit is equal to
- (A) R/Z
- (B) Cosine of phase angle difference between current
and voltage
- (C) Ratio of useful current to total current Iw/I
- (D) All above
9. In a purely inductive circuit
- (A) Actual power is zero
- (B) Reactive power is zero
- (C) Apparent power is zero
- (D) None of above is zero
10. Time constant of an inductive circuit
- (A) Increases with increase of inductance and decrease
of resistance
- (B) Increases with the increase of inductance
and the increase of resistance
- (C) Increases with decrease of inductance and
decrease of resistance
- (D) Increases with decrease of inductance and increase
of resistance
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