What is the value of inductance L for which the current is maximum in a series LCR circuit with C = 10μF and ω = 1000s-1?
100 mH
1 mH
Cannot be calculated unless R is known
10 mH
An alternating voltage E = 200 sin 300 t is applied across a series combination of R = 10 Ω and an inductor 800 mH. The power factor of the circuit is
0.022
0.065
0.042
0.084
An alternating voltage E = 220√2 sin 100 t is connected to 1μF capacitor through an a.c. ammeter. The reading of the ammeter shall be
22 mA
10 mA
40 mA
80 mA
An alternating voltage (in volts) given by
V = 200 √2 sin (100 t), is connected to a 1 μF capacitor through an AC ammeter. The reading of the ammeter will be
20 mA
The effective value of an alternating current is 5A. The current passes through 24 Ω resistor. The maximum potential difference across the resistor is
10 V
170 V
17 V
1700 V
In an LCR series circuit, the capacitance is made one-fourth when in resonance. Then what should be the change in inductance so that the circuit remains in resonance?
4 times
¼ times
8 times
2 times
A coil of inductive reactance 31 Ω has a resistance of 8 Ω. It is placed in series with the condenser of capacitative reactance 25 Ω. The combination is connected to an AC source of 110 V. The power factor of the circuit is
0.56
0.64
0.80
0.33
The time constant of C - R circuit is
1/CR
C/R
CR
R/C
Energy needed to establish an alternating current I in a coil of self inductance L is
L di/dt
zero
LI2/2
IL2/2
The reactance of a capacitor of capacitance C is X. If both the freqauency and capacitance be doubled, then new reactance will be
X
2X
4X
X/4