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 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
In an AC circuit with voltage V and current i the power dissipated is
Depends on the phase between V and i
1/√2 Vi
½ Vi
Vi
Energy needed to establish an alternating current I in a coil of self inductance L is
L di/dt
zero
LI2/2
IL2/2
An a.c. circuit having an inductor and a resistor in series, draws a power of 560 W from an a.c. source marked 210 V, 60 Hz. If power factor of the circuit is 0.8, then impedance of the circuit is
103 Ω
63 Ω
12 Ω
114 Ω
A wire of resistance R is connected in series with an inductor of reactance ωL. Then quality factor of RL circuit is
An AC supply gives 30 Vrms which passes through a 10 Ω resistance. The power dissipated in it is
90 √2 W
90 W
45√2 W
45 W
The time constant of C - R circuit is
1/CR
C/R
CR
R/C
A L-C circuit is in a state of resonance. If C = 0.1 μF and L = 0.25 H, then neglecting the ohmic resistance of the circuit, find the frequency of oscillations.
1007 Hz
100 Hz
109 Hz
500 Hz
The inductive reactance of a coil of 0.2 H inductance at a frequency of 60 Hz is
75.4 Ω
7.54 Ω
0.754 Ω
7.54 × 10-3 Ω
