A rod of insulating material is given a positive charge by rubbing it with a piece of fabric and the fabric is then tested for electric charges.The fabric is repeated to have
A positive charge equal to that of the rod.
Negative charge equal to that on the rod.
A positive charge less than that on the rod.
A negative charge greater than that of the rod.
Two charges q1 and q2 are seperated by a distance d in air.A dielectric slab of thickness t of relative permittivity k is introduced between them.The force between the two charges is nearly given by
1/4πεo q1q2/(d-t)2
1/4πεo q1q2/(d-t+t/k)2
1/4πεo q1q2/(d-t+t√k)2
1/4πεo q1q2/(d+kt)2
An electron kept in an electric field of strength E experiences a force equal to its weight.If m is the mass of electron,the value of E is equal to
mg
mg/e
mg/e2
e/mg
An electron moves along x direction with a uniform speed.An electric field is applied along the Z direction.The path of the electron will be
A parabola is x-7 plane
A circle is x-7 plane
A parabola is x-Z plane
A straightline along Z axis
The radius of hydrogen atom is 5*10-11 m and the charge on electron or proton is of magnitude 1.6*10-11 c. At ground state,the dipole moment of the atom is
8*10-30cm
16*10-30cm
0 cm
4*10-30cm
The ratio of the force between two point charges in air and is a medium of dielectric constant K is
K:1
1:K
K2:1
√K:1
Insulted copper spheres of radii 0.1m and 0.15m and having equal charges are connected by a copper wire and separated then
both spheres will have the same charge
smaller sphere will have greater charge.
bigger sphere will have greater greater charge
Charge on either sphere becomes zero.
Two conducting spheres of radii 5cm and 3cm are equally charged.The ratio of the electric fields on their surfaces will be
3:5
5:3
9:25
25:9
A given charge situated at a certain distance from on electric dipole in the end on position experiences a force F.If the distance of the charge is doubled the force will be
2F
F/2
F/4
F/8
Two particles of masses m and 2m with charges q and are placed in a uniform electric field E and allowed to move for the same time.The ratio of their kinetic energies will be
2:1
1:2
4:1
1:4
