Multiple Choice QuestionsIn a circuit, the current lags behind the voltage by a phase difference of π/2, the circuit will contain which of the following?
Only R
Only C
R and C
Only L
In order to obtain time constant of 10 s in an RC circuit containing a resistance of 103Ω, the capacity of the condenser should be :
10 μF
100 μF
1000 μF
10000 μF
An a-particle, when accelerated through a potential difference of V volt, has a wavelength λ associated with it. In order to have the same λ, by what potential difference a proton must be accelerated?
8 V
6 V
4 V
12 V
The power factor of a series LCR circuit when at resonance is :
zero
0.5
1.0
Depends on values of L, C and R
For high frequency, capacitor offers :
more resistance
less resistance
zero resistance
none of these
In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor, when the energy is stored equally between the electric and magnetic field is :
An LC circuit is in the state of resonance. If C = 0.1 F and L = 0.25 H, neglecting ohmic resistance of the circuit, what is the frequency of oscillations?
1007 Hz
100 Hz
109 Hz
500 Hz
A coil having resistance of 50 ohm and an inductance of 10 ohm, is connected to a 100 volt battery. The energy stored in the coil is
10 J
20 J
30 J
40 J
A capacitor when charged by a potential difference of 200 volt, stores a charge of 0.1 C. By discharging, energy liberated by the capacitor is
-30 J
-15 J
10 J
20 J
The core used in transformer and other electromagnetic instruments is laminated, the reason is
to increase the electric field
to increase the magnetic field
to reduce the loss of energy due to eddy currents
to decrease the resistance
