Alternating Current MCQs Answer

MCQ 1: If a secondary coil has 40 turns, and, a primary coil with 20 turns is

charged with 50 V of potential difference, then the potential difference in the

secondary coil would be

A. 50 V in secondary coil

B. 25 V in secondary coil

C. 60 V in secondary coil

D. 100 V in secondary coil

Right Answer: 100in secondary coil

MCQ 2: Generators at a power station produce electric power at voltage

A. 45 kW

B. 50 kW

C. 60 kW

D. 25 kW

Right Answer: 25 kW

MCQ 3: Equation which measures alternating voltage is

A. Vsin ω

B. sin t

C. Vo sinωt

D. V=IR

Right Answer: Vo sinωt

MCQ 4: In transformer, alternating current is induced in

A. primary coil

B. secondary coil

C. iron core

D. resistor

Right Answer: secondary coil

MCQ 5: High voltages lead to

A. less power loss

B. more power loss

C. high current

D. high resistance

Right Answer: less power loss

MCQ 6: Graph of alternating current is a

A. cos wave

B. tan wave

C. curve

D. sine wave

Right Answer: sine wave

MCQ 7: A component that allows only unidirectional current to pass through it

is

A. resistor

B. inductor

C. transformer

D. diode

Right Answer: diode

MCQ 8: Average power dissipated in resistor if sinusoidal p.d of peak value 25

V is connected across a 20 Ω resistor is

A. 15.6 W

B. 15 W

C. 16 W

D. 17 W

Right Answer: 15.6 W

MCQ 9: Amount of d.c voltage as compare to Vo is

A. 50%

B. 60%

C. 70%

D. 80%

Right Answer: 70%

MCQ 10: A well designed transformer loses power under

A. 10%

B. 1.20%

C. 0.1%

D. 20%

Right Answer: 0.1%

MCQ 11: Ratio of voltages is equal to ratio of

A. iron sheets in core

B. coil

C. number of turns in coil

D. all of above

Right Answer: number of turns in coil

MCQ 12: Process in which A.C is converted into D.C is called

A. induction

B. rectification

C. inversion

D. dispersion

Right Answer: rectification

MCQ 13: Steady d.c voltage is also known as

A. square velocity

B. root mean square velocity

C. root velocity

D. velocity

Right Answer: root mean square velocity

MCQ 14: Ratio of voltages is inverse ratio of the

A. transformer

B. resistor

C. iron core

D. current

Right Answer: current

MCQ 15: If output voltage is greater than input voltage, then transformer is

A. step up

B. step down

C. faulty

D. fatal

Right Answer: step up

MCQ 16: Highest point on AC graph is known as

A. peak value

B. amplitude

C. frequency

D. wave front

Right Answer: peak value