Figure shows the electric lines of forces emerging from a charged body. If the electric field at A and B are EA and EB respectively and if the displacement between A and B is r, then
EA > EB
EA < EB
EA = EB/r
EA = EB / r2
A small piece of metal wire is dragged across the gap between the pole pieces of a magnet in 0.4 sec. If magnetic flux between the pole pieces is known to be 8 × 10-4 Wb, then induced emf in the wire, is
4 × 10-3 V
8 × 10-3 V
20 × 10-3 V
6 × 10-3 V
The unit of permittivity () of space is
newton-metre2 / coulomb2
coulomb / newton-metre
coulomb / newton-metre2
coulomb2 / newton-metre2
Two charges each of equal magnitude 3.2 x 10-19 coulomb but of opposite sign form an electric dipole. The distance between the two charges is 2.4 . If the dipole is placed in an electric field of 5 x 105 volt/metre, then in equilibrium its potential energy will be
3 × 15-23 joule
-3.84 × 10-23 joule
-6 × 10-23 joule
-2 × 10-26 joule
An electron is moving with velocity v on a circular path of radius r in a transverse electric field B. The specific charge (e/m) of the electron is
Two spheres of same metal have radii a and b. Thet have been connected to a conducting wire. Find the ratio of the electric field intensity upon them.
b2 / a
Using mass (M), length (L), time (T ) and current (A) as fundamental quantities, the dimension of permeability is
[ M-1 L T-2 A ]
[ M L2 T-2 A-1 ]
[ M L T-2A-2 ]
[ M L T-1 A-1 ]
Length cannot be measure by
A fermi is equivalent to a femtometer and it is older non-SI measurement unit of length.
A micron is a unit of measure in the system equal to 1 millionth of a meter in length ( about 39 millionths of an inch ).
The light-year is a unit of length used to express astronomical distances and measures about 9.46 trillion kilometers ( 9.46 × 1012 km )
Debye is the unit of electric dipole moment. Therefore length cannot be measured by debye.