1. The capacitors used in filter circuits of power supplies having output voltage more then 450 V mainly are
(a) ceramic capacitors.
(b) electrolytic capacitors.
(c) mica capacitors.
(d) paper capacitors.
Answer ⇓
2. For the normal operation, a varactor diode is always
(a) forward biased.
(b) reverse biased.
(c) needed to input supply.
(d) none of the above.
Answer ⇓
3. If current flowing through a circuit or device increases as the applied voltage is increased, we say that the circuit or device has
(a) inductive nature.
(b) capacitive nature.
(c) positive resistance.
(d) negative resistance.
Answer ⇓
4. Varactor diode act as a
(a) variable capacitor.
(b) voltage regulator.
(c) rectifier.
(d) all of the above.
Answer ⇓
5. Voltage power supplies use a high resistance across the output of the supply. That resistance is called
(a) high Voltage resistors.
(b) potentiometers.
(c) bleeder resistors.
(d) holding resistors.
Answer ⇓
6. Sometime a capacitor is placed in series with the primary of a transformer because
(a) it reduce the ripples in signal.
(b) it raises the power factor of the circuit.
(c) it reduced the noise level.
(d) all of the above.
Answer ⇓
7. The capacitors used in filter circuits of power supply having output voltage less than 100 V are
(a) paper capacitors.
(b) ceramic capacitors.
(c) electrolytic capacitors.
(d) variable capacitor.
Answer ⇓
8. The common collector collection of a transistor has
(a) very high output resistance.
(b) very low input resistance.
(c) very high input resistance.
(d) none of the above.
Answer ⇓
9. The common emitter transistors are used for
(a) high frequency applications.
(b) audio frequency applications.
(c) impedance Matching.
(d) none of the above.
Answer ⇓
10. Input resistance of a common base transistor is
(a) zero.
(b) low.
(c) high.
(d) very high.
Answer ⇓
11. The common collector transistor are used for
(a) high frequency applications.
(b) audio frequency applications.
(c) low frequency applications.
(d) impedance Matching.
Answer ⇓
12. The common base transistors are used for
(a) high frequency applications.
(b) audio frequency applications.
(c) low frequency applications.
(d) impedance Matching.
Answer ⇓
13. Vacuum tubes are preferred for the amplification of
(a) low power signals.
(b) low frequency signals.
(c) audio frequency signals.
(d) high power and high frequency signals.
Answer ⇓
14. In cutoff state, the collector current in a transistor is
(a) approximately zero.
(b) low.
(c) high.
(d) approaches infinity.
Answer ⇓
15. What happened to the base current if base of a transistor is made thick?
(a) base current will decrease.
(b) base current will remain same.
(c) base current will increase.
(d) base current will zero.
Answer ⇓
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