A.C Fundamentals, Circuits and Circuit Theory MCQs

Question 1

In a sine wave the slope is constant

Accepted Answer

No where

Answer

Between 0° and 90°

Answer

Between 90° and 180°

Answer

Between 180° and 270°

Question 2

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

Accepted Answer

Square wave

Answer

Half wave rectified sine wave

Answer

Triangular wave

Answer

Sine wave

Question 3

In a R-L-C circuit

Accepted Answer

All above are correct

Answer

Power is consumed in resistance and is equal to IR

Answer

Exchange of power takes place between inductor and supply line

Answer

Exchange of power takes place between capacitor and supply line

Question 4

Inductance of coil

Accepted Answer

Decreases with the increase in supply frequency

Answer

Is unaffected by the supply frequency

Answer

Increases with the increase in supply frequency

Answer

Becomes zero with the increase in supply frequency

Question 5

Power factor of the following circuit will be unity

Accepted Answer

Resistance

Answer

Inductance

Answer

Capacitance

Answer

Both A and B

Question 6

The voltage of domestic supply is 220 V. This figure represents

Accepted Answer

r.m.s. value

Answer

Mean value

Answer

Peak value

Answer

Average value

Question 7

A parallel AC. circuit in resonance will

Accepted Answer

Have a high impedance

Answer

Have a high voltage developed across each inductive and capacitive section

Answer

Act like a resistor of low value

Answer

Have current in each section equal to the line current

Question 8

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

Accepted Answer

127.4 V

Answer

141.4 V

Answer

282.8 V

Answer

200 V

Question 9

The product of apparent power and cosine of the phase angle between circuit voltage and current is

Accepted Answer

True power

Answer

Reactive power

Answer

Volt-amperes

Answer

Instantaneous power