MCQ
1721. In an AC circuit, a low value of KVAR compared with kW indicates-
Low efficiency
High-power factor
Unity power factor
Maximum load current
1722. Magnitude of current at resonance in R-L-C circuit-
Depends upon the magnitude of R
Depends upon the magnitude of L
Depends upon the magnitude of C
Depends upon the magnitude of R, L and C
1723. The double energy transient occur in the-
R-L circuit
R-C circuit
R-L-C circuit
Purely inductive circuit
1724. What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value and the other is at zero value?
45°
90°
180°
30°
1725. Pure inductive circuit takes power from the A.C. line, when-
Applied voltage decreases but current increases
Applied voltage increases but current decreases
Both applied voltage and current increase
Both applied voltage and current decrease
1726. --- Power factor of the following circuit will be zeгo.
Resistance
Inductance
Capacitance
Both (b) and (c)
1727. Capacitive reactance is more, when-
Capacitance is less and frequency of supply is less
Capacitance is less and frequency of supply is more
Capacitance is more and frequency of supply is less
Capacitance is more and frequency of supply is more
1728. A capacitor opposes---
charge in current
charge in voltage
both charge in current and voltage
none
1729. An air-core choke coil and an electric bulb are connected in series with ac mains. On introducing soft iron bar in the coil, the intensity of light will-
fluctuate
remain unchanged
increase
decrease
1730. How long does it take 50 µC of charge to pass a point in a circuit if the current flow is 15 mA?
3.33 x 10^3s
6 x 10^3s
6.33 × 10^3s
2s
1731. The capacitance of a capacitor is influented by-
Plate thickness
Plate separation
Plate area
Both (b) and (c)
1732. If positive phase sequence of 3-0 load is 'abc', the negative sequence is-
bac
cba
ach
all of the above
1733. In any A.C. circuit always-
Apparent power is more than actual power
Reactive power is more than apparent power
Actual power is more than reactive power
Reactive power is more than actual power
1734. If the power factor of a circuit is unity, its reactive power is-
a maximum
zero
quantity
equal to FR
1735. Pure inductive circuit-
Consumes some power on average
Does not take power at all from a line
Takes power from the line during some parts of the cycle and then returns back to it during
other parts of the cycle None of the above
1736. Which resistor will be physically larger in size-
10Ω 50W
100Ω 10W
1ΜΩ 1W
1KΩ 1W
1737. What quantity of charage must be delivered by a battery with a potential difference of 100 V to do 500) of work?
5C
50C
0.5C
500C
1738. Which of the following statements pertains to resistors only?
Can dissipate considerable amount of power
Can act as energy storage devices
Connecting them in parallel increases the total value
Oppose sudden changes in voltage
1739. In a highly capacitive circuit, the-
Apparent power is equal to the actual power
Reactive power is more than the apparent power
Reactive power is more than the actual power
Actual power is more than its reactive power
1740. One watt-hour is equal to-
360 Joule
300 Joule
3000 Joule
3600 Joule