# ONLINE MCQ EE AND ECE-A.C. Fundamentals, Circuits and Circuit Theory Part 5

1. The apparent power drawn by an A.C. circuit
is 10 kVA and active power is 8 kW. The reactive power in the circuit is
(A) 4 kVAR
(B) 6 kVAR
(C) 8 kVAR
(D) 16 kVAR

2. In a sine wave the slope is constant

(A) Between 0° and 90°
(B) Between 90° and 180°
(C) Between 180° and 270°
(D) No where

3. The r.m.s. value of pure cosine function is

(A) 0.5 of peak value
(B) 0.707 of peak value
(C) Same as peak value
(D) Zero

4. In a pure capacitive circuit if the supply
frequency is reduced to 1/2, the current will

(A) Be reduced by half
(B) Be doubled
(C) Be four times at high
(D) Be reduced to one fourth

5. Capacitors for power factor correction are rated in

(A) kW
(B) kVA
(C) kV
(D) kVAR

6. The reactance offered by a capacitor to
alternating current of frequency 50 Hz is 20 Q. If frequency is increased to
100 Hz, reactance becomes __________ ohms.

(A) 2.5
(B) 5
(C) 10
(D) 15

7. 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

8. The r.m.s. value of a sinusoidal A.C.
current is equal to its value at an angle of ________ degrees.

(A) 90
(B) 60
(C) 45
(D) 30

9. 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

10. In the case of an unsymmetrical alternating
current the average value must always be taken over

(A) Unsymmetrical part of the wave form
(B) The quarter cycle
(C) The half cycle
(D) The whole cycle

Show and hide multiple DIV using JavaScript

.main_div{text-align:left;}
.inner_div{margin-top:5px;}
.buttons a{font-size: 15px;}
.buttons a:hover{cursor:pointer; font-size: 15px;}