# Series Parallel RLC Circuit MCQ

(a) 90o
(b) 45o lag

(a) 10 A
(b) 5 A
(c) 3.75 A
(d) 2.5 A

(a) 2V
(b) 4 V
(c) 8 V
(d) 16 V

(a) 45o lagging
(c) 90o lagging

(a)
(b)
(c)
(d)

### 6. Capacitive susceptance is a measure of

(a) a purely capacitive circuit’s ability to pass current.
(b) a purely capacitive circuit’s ability to resist the flow of current.
(c) the extent of neutralization of reactive power in a circuit.
(d) reactive power in a circuit.

(a) 43.7 µF
(b) 4.37 µF
(c) 437 µF
(d) 4.37 µF

### 8. In an RLC circuit, supplied from AC source, the reactive power is proportional to the

(a) average energy stored in the electric field.
(b) average energy stored in the magnetic field.
(c) sum of the average energy stored in the electric field and that stored in the magnetic field.
(d) difference between the average energy stored in the electric field and that stored in the magnetic field.

### 9. Real part of admittance is ……… and the imaginary part is ……

(a) impedance, resistance
(b) resistance, impedance
(c) susceptance, inductance
(d) conductance, susceptance

(b) ac + bd

### 11. A square wave is fed to an R – C circuit. Then

(a) voltage across R is square and across C is not square.
(b) voltage across C is square and across R is not square.
(c) voltage across both R and C is square.
(d) voltage across both R and C is not square.

### 12. A 100 W, 100 V bulb is to be supplied from 220 V, 50 Hz supply. Which of the following arrangements is preferable?

(a) Additional pure inductance in series with lamp.
(b) Additional resistance in series with the lamp.
(c) Additional inductance and capacitance in series with the lamp.

### 13. With the increase in applied frequency, the dielectric loss in a material will

(a) increase.
(b) decrease.
(c) remain constant.

(a) 0.5 lagging.
(c) unity.
(d) zero.

### 15. The current through a series RLC circuit under resonance condition will be

(a) V/R
(b) V/XC
(c) V/XL
(d) none of these

### 16. Consider the following statements

When a series R-L-C circuit is under resonance

1. current is maximum through R.
2. magnitude of the voltage across L is equal to that across C.
3. the power factor of the circuit is unity.

Which of the statements given above are correct?
(a) 1, 2 and 3
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1 and 3 only

### 17. At resonant frequency an R-L-C circuit draws maximum current due to the reason that

(a) the difference between capacitive reactance and inductive reactance is zero.
(b) the impedance is more than resistance.
(c) the voltage across the capacitor equals the applied voltage.
(d) the power factor is less than unity.

### 18. Consider the following statements with respect to a series R-L-C circuit under resonance condition:

1. All the applied voltage appears across R.
2. There is no voltage across either L or C.
3. The voltage across L and C equal and equal to their maximum values.

Out of these statements
(a) 1 alone is correct.
(b) 2 alone is correct.
(c) 1 and 3 are correct.
(d) 1 and 2 are correct.

(a) 1/LC
(b) 1/ω√(LC)
(c) 1/ ω2LC
(d) 1/2π√(LC)

### 20. Consider the following statements:

In a network of resonance

2. The power factor is unity irrespective of the network.
3. The Q of a series RLC resonant circuit is independent of R.

Out of these statements
(a) 1 and 3 are correct.
(b) 1 and 2 are correct.
(c) 2 and 3 are correct.
(d) 1 alone is correct.

(a) 2fo
(b) Still fo
(c) fo/4
(d) fo/2

### 22. In a series RLC circuit at resonance, the magnitude of voltage devolped across the capacitor

(a) is always zero.
(b) can never be greater than the input voltage.
(c) can be greater than the input voltage however, it is 90o out of phase with the input voltage.
(d) can be greater than the input voltage and is in phase with the input voltage.

(a) 200 V
(b) 1788 V
(c) 1800 V
(d) 2000 V

### 24. In a series RLC circuit, the maximum voltage across the capacitor occurs at a frequency

(a) double the resonant frequency.
(b) equal to the resonant frequency.
(c) √2 times the resonant frequency.
(d) below the resonant frequency.

### 25. In a series RLC circuit, the maximum voltage across the inductor occurs frequency

(a) at resonant the frequency.
(b) just after the resonant frequency.
(c) just before the resonant frequency.
(d) just before and after the resonant frequency.

### 26. A series circuit having a resonant frequency of 60 KHz is connected in series with a signal generator which produces signals of frequencies of 20, 30, 40 and kHz. The signals experiencing minimum and maximum impedances will be

(a) 60 kHz and 20 kHz respectively.
(b) 20 kHz and 60 kHz respectively.
(c) 30 kHz and 60 kHz respectively.
(d) 20 kHz and 40 kHz respectively.

(a) 0.5
(b) 2
(c) 2.5
(d) 50

### 28. When Q – factor of a circuit is high, then

(a) power factor of the circuit is high.
(b) impedance of the circuit is high.
(c) bandwidth is large.
(d) none of these.

### 29. A high Q coil has

(a) large bandwidth.
(b) high losses.
(c) low losses.
(d) flat response.

### 30. In a series resonant circuit, with the increase in L

(a) resonant frequency will decrease.
(b) bandwidth will decrease.
(c) Q will increase.
(d) all of the above.

### 31. In a series resonant circuit, with the increase in C

(a) resonant frequency will decrease.
(b) Q will decrease.
(c) bandwidth will decrease.
(d) both (a) and (b).

### 32. Which of the following will not be affected due to change in R?

(a) Bandwidth
(b) Q
(c) Resonant frequency
(d) None

### 33. Change in circuit voltage will affect

(a) Resonant frequency
(b) Q
(c) Current
(d) Bandwidth

### 34. Higher the Q of a series circuit, narrower its

(a) pass-band.
(b) resonant curve.
(c) bandwidth.
(d) all of these.

### 35. An RLC series circuit has f1 and f2 as the half power frequencies and fo as the resonant frequency. The Q factor of the circuit is given by

(a) (f1 + f2)/2fo
(b) (f1 – fo)/(f2 – fo)
(c) fo/(f1 – f2)
(d) (f1 – f2)/fo

### 36. Resonant frequency fr of a series RLC circuit is related to half power frequencies f1 and f2 as

(a) fr = (f1 + f2)/2
(b) fr = √(f1f2)
(c) fr = f2 – f1
(d) fr = √f1 + √f2

### 37. An RLC series circuit has f1 and f2 the half power frequencies and fr as the resonant frequency. The selectivity of the circuit is given by

(a) (f1 + f2)/fr
(b) (f2 – f1)/2fr
(c) (f2 – f1)/fr
(d) None of these

### 38. In an RLC resonant circuit, if inductance of the circuit is made double and the capacitance is made half, which of the following will be affected?

(a) Resonant frequency.
(b) Selectivity of the circuit.
(c) Current at resonant frequency.
(d) Impedance at resonant frequency.

### 39. At resonance, the parallel circuit of Figure below constituted by an iron-cored coil and a capacitor behaves like:

(a) an open circuit.
(b) a short circuit.
(c) a pure resistor of value R
(d) a pure value of resistor of value much higher than R.

### 40. When resonant frequency of an RLC parallel circuit is given by 1/2π√(LC), the essential condition is that

(a) impedance must be non-resistive.
(b) capacitance must be non-leaky.
(c) current is minimum at resonance.
(d) all of the above.

(a) LC/RL
(b) LCRL
(c) C/(LRL)
(d) L/(CRL)

(a) capacitive.
(b) inductive.
(c) susceptive.
(d) conductive.

### 43. In order to tune a parallel resonant circuit to a lower frequency, the capacitance must

(a) be increased.
(b) be decreased.
(c) be zero.
(d) remain the same.

### 44. Consider the following statements:

If a high Q parallel resonant circuit is loaded, then

1. the circuit impedance reduces.
2. the resonant frequency reduces.
3. the bandwidth reduces.

Which of the statements given above is/are correct?
(a) 1 and 2 only.
(b) 1 only.
(c) 2 and 3 only.
(d) 1, 2 and 3.

### 45. A circuit has two parallel branches. In one branch, R and L are connected in series while in the other R and C are connected in series. If R = √(L/C), which one of the following is not correct?

(a) The circuit is in resonance.
(b) The two branch currents are in quadrature.
(c) The circuit has impedance independent of its frequency.
(d) The two branch currents are in phase.

### 47. A parallel resonant circuit can be employed

(a) as a high impedance.
(b) to reject a small band of frequencies.
(c) to amplify voltage.
(d) both (a) and (b).

### 48. In series as well as parallel resonant circuit, increase in resistance would cause

(a) increase in bandwidth of both the circuits.
(b) decrease in bandwidth of both the circuits.
(c) decrease in bandwidth in series circuit and increase in bandwidth in parallel circuit.
(d) increase in bandwidth in series circuit and decrease in bandwidth in parallel circuit.

## Series Parallel RLC Circuit MCQ

© www.yourelectricalguide.com/ series parallel rlc circuit mcq.