A.C. Fundamentals

Power factor of the following circuit will be unity

A. inductance
B. capacitance
C. resistance
D. both A. and B.

Power factor of an inductive circuit is usually improved by connecting capacitor to it in____________?

A. parallel
B. series
C. either A. or (b)
D. none of the above

All the rules and laws of D.C. circuit also apply to A.C. circuit containing_____________?

A. capacitance only
B. inductance only
C. resistance only
D. all above

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

Power factor of an electrical circuit is equal to____________?

A. R/Z
B. cosine of phase angle difference be-tween current and voltage
C. kW/kVA
D. ratio of useful current to total cur¬rent Iw/I
E. all of these

In a series resonant circuit, the impedance of the circuit is___________?

A. minimum
B. maximum
C. zero
D. none of the above

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

For the same peak value which of the following wave will ‘have the highest r.m.s. value?

A. square wave
B. half wave rectified sine wave
C. triangular wave
D. sine wave

The power consumed in a circuit element will be least when the phase difference between the current and voltage is__________?

A. 180″
B. 90°
C. 60°
D. 0°

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. 200V