A capacitor is connected to a cell of emf E having some internal resistance r, The potential difference across the :
cell is < E
cell is E
capacitor is > E
capacitor is < E
B.
cell is E
When a capacitor is fully charged, it draws no current. When no current flows in the circuit, the potential difference across the cell
= emf of the cell = potential difference across the capacitor
An electron moves at a right angle to a magnetic field of 1.5 x 10-2 tesla with a speed of 6 x 107 m/s. If the specific charge of the electron is 1.7 x 1011 coulomb/kg, the radius of the circular path will be
2.9 cm
3.9 cm
2.35 cm
2 cm
The figure shows three points A, B and C in a region of a uniform electric field . The line AB is perpendicular and BC is parallel to the field lines. Then which of the following holds good?
VA = VB = VC
VA = VB > VC
VA = VB < VC
VA > VB = VC
A short linear object of length b lies along the axis of a concave mirror of focal length f at a distance u from the pole of the mirror, what is the size of the image?
The minimum wavelength of X-rays emitted by X-ray tube is 0.4125 Å. The accelerating voltage is :
30 kV
50 kV
80 kV
60 kV
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 bar magnet of magnetic moment is placed in the magnetic field . The Torque acting on the magnet is :
A capacitor of capacitance 6 µF is charged upto 100 volts. The energy stored in the capacitor is :
0.6 joule
0.06 joule
0.03 joule
0.3 joule