# MCQs on Electrical Circuit Theory

1. Ohm’s law is not applicable to
(a) high voltage.
(b) high current.
(c) DC circuits.
(d) semiconductor.

2. The power factor of pure inductive circuit is
(a) zero.
(b) positive.
(c) negative.
(d) unity.

3. Which of the following bridge is used to measure low resistance?
(a) Wein bridge.
(b) Wheat stone bridge.
(c) Kelvin bridge.
(d) None of the above.

4. Which of the following is generally used to made a voltage dependent resistor?
(a) phosphorus.
(b) silicon carbide.
(c) carbon.
(d) nichrome.

5. At what temperature the resistivity of mercury is zero?
(a) 270 K
(b) 180 K
(c) 4 K
(d) 100 K

6. For drawing vector diagram for a series circuit, the reference vector is
(a) current.
(b) voltage.
(c) resistance.
(d) reactance.

7. As the frequency increases, wavelength of signal is
(a) increases.
(b) decreases.
(c) remains same.
(d) none of the above.

8. AC ammeter and voltmeter generally determine the
(a) maximum value.
(b) average value.
(c) r.m.s. value.
(d) peak to peak value.

9. In a series resonant circuit, the impedance of the circuit is
(a) minimum.
(b) zero.
(c) maximum.
(d) infinite.

10. The power factor of series resonant circuit is
(a) zero.
(b) unity.
(c) 0.65.
(d) none of the above.

11. The main purpose of using voltage dependent resistor in a circuit is to
(a) limit the current.
(b) avoid overheating.
(c) suppress surge.
(d) provide variable voltage.

12. Resistance of a wire is ” r ” ohm. The wire is stretched to double its length, then its resistance in ohm is
(a) r/2.
(b) 4r.
(c) 2r.
(d) r/4.

13. If an electric current of 6 amp flow in a circuit, it is the same as
(a) 6 Coulomb/sec.
(b) 6 watt/sec.
(c) 6 joule/sec.
(d) 6 volt/sec.

14. When the supply frequency of an AC circuit increases, its capacitive reactance is
(a) decreases.
(b) increases.
(c) remain same.
(d) none of the above.

15. As the temperature of NTC thermistor increases, its resistance
(a) decreases.
(b) increases.
(c) remain same.
(d) none of the above.

« BACK                                        NEXT »