# Practice Test: Question Set - 10

**1. The peak value of a sine wave is 200 V. Its average value is**

- (A) 127.4 V

- (B) 141.4 V

- (C) 282.8 V

- (D) 200 V

**2. The inductance of a coil can be increased by**

- (A) Increasing core length

- (B) Decreasing the number of turns

- (C) Decreasing the diameter of the former

- (D) Choosing core material having high relative
permeability

**3. For a sine wave with peak value I**

_{max}the r.m.s. value is- (A) 0.5 I

_{max}

- (B) 0.707

- (C) 0.9

- (D) 1.414 I

_{max}

**4. For a frequency of 200 Hz, the time period will be**

- (A) 0.05 s

- (B) 0.005 s

- (C) 0.0005 s

- (D) 0.5 s

**5. The ratio of active power to apparent power is known as factor.**

- (A) Demand

- (B) Load

- (C) Power

- (D) Form

**6. The best place to install a capacitor is**

- (A) Very near to inductive load

- (B) Across the terminals of the inductive load

- (C) Far away from the inductive load

- (D) Any where

**7. Inductance of a coil Varies**

- (A) Directly as the cross-sectional area of
magnetic core

- (B) Directly as square of number of turns

- (C) Inversely as the length of the iron path

- (D) As (A) to (C)

**8. Power factor of the following circuit will be unity**

- (A) Inductance

- (B) Capacitance

- (C) Resistance

- (D) Both (A) and (B)

**9. The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces**

- (A) The more heat than produced by A.C. when flowing
through the same circuit

- (B) The same heat as produced by A.C. when flowing
through the same circuit

- (C) The less heat than produced by A.C. flowing through
the same circuit

- (D) None of the above

**10. In a pure resistive circuit**

- (A) Current lags behind the voltage by 90°

- (B) Current leads the voltage by 90°

- (C) Current can lead or lag the voltage by 90°

- (D) Current is in phase with the voltage

**11. Time constant of a circuit is the time in seconds taken after the application of voltage to each**

- (A) 25% of maximum value

- (B) 50% of maximum value

- (C) 63% of maximum value

- (D) 90% of the maximum value

**12. What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value?**

- (A) 0°

- (B) 45°

- (C) 90°

- (D) 180°

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