MCQs Electrical EngieeringĀ 

1. Power factor in an industry can be improved by :
(1) TransformersĀ  Ā  Ā  Ā  Ā  Ā 
(2) CapacitorsĀ 
(3) InductorsĀ  Ā  Ā  Ā  Ā  Ā 
(4) StabilizersĀ  Ā  Ā  Ā  Ā  Ā  Ā  Ā 
AnsĀ  (2)
2. The power factor of a pure capacitive circuit is :
(1) MaximumĀ  Ā 
(2) UnityĀ 
(3) 0.8 leadingĀ  Ā  Ā  Ā 
(4) ZeroĀ  Ā  Ā  Ā  Ā  Ā  Ā  Ā 
AnsĀ  (4)
3. A circuit requires a capacitor of 100šœ‡š‘“, 25V. The capacitor can be :
(1) Paper capacitorĀ  Ā  Ā  Ā 
(2) Electrolytic capacitorĀ 
(3) Ceramic capacitorĀ  Ā 
(4) Any type of capacitorĀ  Ā 
AnsĀ  (2)
4. A capacitor oposis :
(1) Change in currentĀ 
(2) Change in Voltage
(3) Both change in current and voltageĀ 
(4) Non of theseĀ  Ā  Ā  Ā 
AnsĀ (2)
5. The reactance of 1 farad capacitance when connected to a DC circuit is
(1) infiniteĀ  Ā  Ā  Ā  Ā 
(2) 1š›ŗ
(3) 0.5Ā  š›ŗĀ Ā Ā Ā Ā Ā Ā Ā Ā Ā Ā 
(4) zero ohmsĀ  Ā  Ā  Ā  Ā  Ā 
AnsĀ  (1)
6. A piece of oil soaked paper has been inserted between the plates of a parallel plate capacitor. Then the potential difference between the plates will
(1) increase
(2) decrease
(3) remain unalteredĀ  Ā  Ā 
(4) become zeroĀ  Ā  Ā  Ā 
AnsĀ  (2)
7. A capacitor with no initial charge at t = ∞ acts :
(1) Current SourceĀ  Ā  Ā  Ā 
(2) Short-CircuitsĀ 
(3) Open-CircuitĀ  Ā  Ā  Ā 
(4) Voltage sourceĀ  Ā  Ā  Ā  Ā  Ā  Ā 
AnsĀ  (3)
8. If a 10-šœ‡F capacitor is connected to a voltage source with v(t) = 50 sin 2000 t V, then the current through the capacitor is .................A .
(1) cos 2000 tĀ Ā Ā Ā Ā Ā Ā 
(2) 500 cos 2000t
(3) 106 cos 2000tĀ Ā Ā Ā Ā 
(4) 5 x 10-4 cos 2000tĀ Ā Ā Ā Ā Ā Ā Ā Ā 
AnsĀ  (1)
9. Two lossy capacitor with equal capacitance values and power factors of 0.01 and 0.02 are in parallel , and the combination is supplied from a sinusoidal voltage source. The power factor of the combination is
(1) 0.03Ā Ā Ā Ā Ā Ā Ā Ā Ā 
(2) 0.015
(3) 0.01Ā Ā Ā Ā Ā Ā Ā 
(4) 0.0002.Ā Ā Ā Ā Ā Ā Ā Ā Ā Ā Ā Ā 
AnsĀ  (2)
10.Ā . Three 3 šœ‡F capacitors are in series. A 6 šœ‡F capacitor is in parallel with this series arrangement. The equivalent capacitance of this combination is
(1) 7šœ‡FĀ Ā Ā Ā Ā Ā Ā Ā 
(2) 15 šœ‡F
(3) 3.6 šœ‡FĀ Ā Ā Ā Ā 
(4) 1 šœ‡FĀ  Ā  Ā  Ā  Ā  Ā  Ā 
AsnĀ  (1)