AC Fundamentals - Electrical Engineering (MCQ) questions and answers

1)   The phasor current through a 200 ohm resistor assuming a voltage of 200Arms at an angle of zero degree applied across it is

a. 1Arms at an angle of zero degree
b. 1Arms at an angle of 45 degree
c. 1Arms at an angle of 90 degree
d. 1Arms at an angle of 180 degree
Answer  Explanation 

ANSWER: 1Arms at an angle of zero degree

Explanation:
No explanation is available for this question!
2)   If the number of turns, area and current of an ac circuit is doubled then the new inductance will be

a. Equal to the former
b. Twice of the former
c. Four times the former
d. Half of the former
Answer  Explanation 

ANSWER: Four times the former

Explanation:
No explanation is available for this question!
3)   If the voltage increases from zero to peak value and decreases back to zero during one alteration, then the average value must be

a. Less than zero
b. Greater than peak value
c. Between zero to peak value
d. None of these
Answer  Explanation 

ANSWER: Between zero to peak value

Explanation:
No explanation is available for this question!
4)   When an ac power is applied to a reactive load, then the voltage is

a. In phase with the current
b. 90 degree out of phase with the current
c. 180 degree out of phase with the current
d. 270 degree out of phase with the current
Answer  Explanation 

ANSWER: 90 degree out of phase with the current

Explanation:
No explanation is available for this question!
5)   A vector quantity has

a. Only magnitude
b. Only direction
c. Both (a) and (b)
d. None of these
Answer  Explanation 

ANSWER: Both (a) and (b)

Explanation:
No explanation is available for this question!
6)   In ac circuitμ the maximum current required is

a. Equal to the effective current
b. 1.414 times the effective current
c. Twice the effective current
d. 1.732 times the effective current
Answer  Explanation 

ANSWER: 1.414 times the effective current

Explanation:
No explanation is available for this question!
7)   The number of instantaneous values between zero and the peak value is

a. Zero
b. One
c. Eleven
d. Infinity
Answer  Explanation 

ANSWER: Infinity

Explanation:
No explanation is available for this question!
8)   Peak to peak value of a sine wave is

a. Equal to the maximum or phase value of sine wave
b. Twice the maximum or phase value of sine wave
c. Half of the maximum or phase value of sine wave
d. Four times the maximum or phase value of sine wave
Answer  Explanation 

ANSWER: Twice the maximum or phase value of sine wave

Explanation:
No explanation is available for this question!
9)   A radian is defined as the central angle, for which length of its arc

a. Should be greater than radius
b. Should be less than radius
c. Should be equal to the radius
d. None of these
Answer  Explanation 

ANSWER: Should be equal to the radius

Explanation:
No explanation is available for this question!
10)   The most common waveforms of ac is

a. Square
b. Triangular
c. Sinusoidal
d. Saw tooth
Answer  Explanation 

ANSWER: Sinusoidal

Explanation:
No explanation is available for this question!

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