1. At what frequency the parallel RL circuit behaves as purely resistive circuit?
(a)low.
(b) high.
(c) very low.
(d) very high.
Answer
2. If the supply frequency of an purely inductive circuit is reduced by half, then the circuit current is
(a)zero.
(b) remain same.
(c) doubled.
(d) reduced by half.
Answer
3. If the supply frequency of an purely capacitive circuit is reduced by half, then the circuit current is
(a)zero.
(b) doubled.
(c) remain same.
(d) reduced by half.
Answer
4. Power factor is a factor which must be multiplied to apparent power to obtain
(a)reactive power.
(b) true power.
(c) wavelength.
(d) phase angle.
Answer
5. When a capacitor and a resistor are connected in series, the current will
(a)lag the voltage.
(b) leads the voltage.
(c) in phase with voltage.
(d) leads voltage by 90°.
Answer
6. For the r.m.s. value of 20 V, the peak to peak value is
(a)14.14.
(b) 22.22.
(c) 28.28.
(d) 56.56.
Answer
7. If the energy stored in the magnetic field of an coil is 10 times the energy wasted in its resistance, the quality factor of that coil is
(a)5.
(b) 2.5.
(c) 10.
(d) 20.
Answer
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