MCQ
6421. In the maximum value of a current of a circuit is 1 amp (sinusoidal wave). What is the R.M.S. value?
1 Amp
0.637 Amp
0.707 Amp
1.5 Amp
6422. 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
6423. The power of an AC circuit is given by-
VI cosθ
FZ
VI sinθ
FXL
6424. If the power factor of a circuit is unity, its reactive power is-
a maximum
zero
quantity
equal to FR
6425. A capacitor opposes---
charge in current
charge in voltage
both charge in current and voltage
none
6426. The capacitance of a capacitor is influented by-
Plate thickness
Plate separation
Plate area
Both (b) and (c)
6427. One watt-hour is equal to-
360 Joule
300 Joule
3000 Joule
3600 Joule
6428. 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
6429. Which resistor will be physically larger in size-
10Ω 50W
100Ω 10W
1ΜΩ 1W
1KΩ 1W
6430. If positive phase sequence of 3-0 load is 'abc', the negative sequence is-
bac
cba
ach
all of the above
6431. 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°
6432. Three equal resistor of 100 is connected in series across a source of Emf 30V. What would be the power consumed by each resistor?
10W
90W
30W
60W
6433. 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
6434. 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
6435. 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
6436. In an AC circuit, a low value of KVAR compared with kW indicates-
Low efficiency
High-power factor
Unity power factor
Maximum load current
6437. 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
6438. 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
6439. What would be the charge of a capacitor 10μF when connected with 20V supply?
200μc
300μc
6200μc
30μc
6440. 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