## AC Fundamentals, Circuit and Circuit Theory The product of apparent power and cosine of the phase angle between circuit voltage and current is

Instantaneous power
Volt-amperes
True power
Reactive power

## AC Fundamentals, Circuit and Circuit Theory Power factor of an electrical circuit is equal to

R/Z
Cosine of phase angle difference between current and voltage
all of these
Ratio of useful current to total current Iw/I

## AC Fundamentals, Circuit and Circuit Theory Inductance affects the direct current flow

Only at the time of turning off
At all the time of operation
Only at the time of turning on
At the time of turning on and off

## AC Fundamentals, Circuit and Circuit Theory The square waveform of current has following relation between r.m.s. value and average value.

r.m.s. value is equal to average value
r.m.s. value of current is less than average value
r.m.s. value of current is greater than average value
None of these

## AC Fundamentals, Circuit and Circuit Theory In a pure inductive circuit

The current is in phase with the voltage
The current can lead or lag by 90°
The current leads the voltage by 90°
The current lags behind the voltage by 90°

R.m.s. value
Peak value
Mean value
Average value