Electric Charges and Fields

A charge q is located at the centre of a cube. The electric flux through any face is

1. 2 q6(4 0)
2. 4 q6(4 0)
3. q6(4 0)
4. q6(4 0)

An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius r. The Coulomb force F between the two is

1. K e2r2 r
2. -K e2r3 r
3. K e2r3 r
4. -K e2r2 r

A dipole of dipole moment p is placed in uniform electric field E then torque acting on it is given by

1. = p E
2. = p E
3. = p + E
4. = p - E

A charge Q is placed at the centre of a cube, the flux coming out from each face will be

1. Q6 0 10-6
2. Q6 0 10-3
3. Q24 0
4. Q8 0

A charge Q is situated at the corner of a cube, the electric flux passed through all the six faces of the cube is

1. Q6 0
2. Q8 0
3. Q 0
4. Q2 0

Electric field at centre O of semicircle of radius a having linear charge density is given as [figure]

1. 2 0 a
2. 0 a
3. 2 0 a
4. 0 a