CBSE
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
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
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
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
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
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
Induced emf in the coil depends upon
conductivity of coil
amount of flux
rate of change of linked flux
resistance of coil
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
The rms speed (in m/s) of oxygen molecules of the gas at temperature 300 K, is
483
504
377
346
In a circuit, L, C and R are connected in series with an alternating voltage source of frequency f. The current leads the voltage by 45°. The value of C is