CBSE
Multiple Choice QuestionsAn 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
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
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
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
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
In 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
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
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 :
In an L-R circuit, the current increases to three fourth of its maximum value in 4 s, then the time constant of the circuit is
2loge 2
