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
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
The potential difference between points A and B is:
20/7 V
40/7 V
10/7 V
zero
D.
zero
From the given figure, the current through the lower branch of resistances which are joined in series is
Again current through an upper branch of resistances which are also connected in series is
Now according to the Kirchhoff's voltage law
VB - VA = 8 × i2 - 4 × i1
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