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
A 12 Ω resistor and a 0.21 H inductor are connected in series to an a.c. source operating at 20 V, 50 Hz. The phase angle between the current and source voltage is :
30o
40o
90o
80o
In an AC circuit, the rms value of current, irms is related to the peak current, i0 by the relation
irms = √2i0
irms = πi0
irms = i0/π
irms = 1/√2 i0
Energy needed to establish an alternating current I in a coil of self inductance L is
L di/dt
zero
LI2/2
IL2/2
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
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
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
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
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
An alternating voltage V = 200√2 sin (100t) is connected to a 1μF capacitor through an AC ammeter. The reading of the ammeter shall be
20 mA