In a series L-C-R circuit, resistance R = 10 Ω and the impedance Z = 10 Ω. The phase difference between the current and the voltage is
0o
30o
45o
60o
The impedance of a circuit, when a resistance R and an inductor of inductance L are connected in series in an AC circuit of frequency f, is
A choke is preferred to a resistance for limiting current in AC circuit because
choke is cheap
there is no wastage of power
choke is compact in size
choke is a good absorber of heat
Induced emf in the coil depends upon
conductivity of coil
amount of flux
rate of change of linked flux
resistance of coil
C.
rate of change of linked flux
According to Faraday's law, "the induced emf in a closed loop equals the time rate of change of magnetic flux through the loop".
i.e
Hence, induced emf in a coil depends on the rate of change of flux.
In an L-C-R circuit inductance is changed from L to L/2.To keep the same resonance frequency, C should be changed to
2 C
4 C
220 V, 50 Hz, AC source is connected to an inductance of 0.2 Hand a resistance of 20 Ω in series. Whatis the current in the circuit?
3.33 A
33.3 A
5 A
10 A
If we change the value of R, then
voltage does not change on L
voltage does not change on LC combination
voltage does not change on C
voltage changes on LC combination
Real power consumption in a circuit is least when it contains.
high R, low L
high R, high L
low R, high L
high R, low C
An inductor (L = 20 H), a resistor (R = 100 Ω) and a battery (E = 10 V) are connected in series. After a long time, the circuit is short-circuited and then the battery is disconnected. Find the current in the circuit at 1 ms after short circuiting.
4.5 x 105 A
3.2x 10-5 A
9.8 × 10-5 A
6.7 × 10-4 A