The voltage reading on the voltmeter V in the circuit shown below will be:
1. zero
2. 100 V
3. 200 V
4. 300 V
A 220 V, 50 Hz ac source is connected to an inductance of 0.2 H and a resistance of 20 ohms in series. What is the current in the circuit :
1. 10A
2. 5A
3. 33.3A
4. 3.33A
The potential difference V and the current i flowing through an instrument in an ac circuit of frequency f are given by volts and I = 2 sin ωt amperes (where ω = 2πf). The power dissipated in the instrument is
(1) Zero
(2) 10 W
(3) 5 W
(4) 2.5 W
The peak value of an alternating e.m.f. E is given by is 10 volts and its frequency is 50 Hz. At time , the instantaneous e.m.f. is
1. 10 V
2.
3. 5 V
4. 1 V
If a current I given by flows in an ac circuit across which an ac potential of has been applied, then the power consumption P in the circuit will be
(1)
(2)
(3)
(4) P = 0
An alternating current of frequency ‘f’ is flowing in a circuit containing a resistance R and a choke L in series. The impedance of this circuit will be:
1. R + 2πfL
2.
3.
4.
A resistance of 300 Ω and an inductance of henry are connected in series to an ac voltage of 20 volts and a 200 Hz frequency. The phase angle between the voltage and current will be:
1.
2.
3.
4.
In a region of uniform magnetic induction B = 10–2 tesla, a circular coil of radius 30 cm and resistance π2 ohm is rotated about an axis that is perpendicular to the direction of B and which forms a diameter of the coil. If the coil rotates at 200 rpm the amplitude of the alternating current induced in the coil is :
(1) 4π2 mA
(2) 30 mA
(3) 6 mA
(4) 200 mA
In a LCR circuit having L = 8.0 henry, C = 0.5 μF and R = 100 ohm in series. The resonance frequency in radian per second is
(1) 600 radian/second
(2) 600 Hz
(3) 500 radian/second
(4) 500 Hz
The impedance of a circuit consists of 3 ohm resistance and 4 ohm reactance. The power factor of the circuit is :
(1) 0.4
(2) 0.6
(3) 0.8
(4) 1.0