Find also the magnitude of the forces when the conductor is parallel and perpendicular to the field.

Two equal charges repel each other with a force of 0.4 newton when situated 10 cm apart in air. Find the magnitude of the force when the charges are in a medium of relative permittivity 4.0

A current carrying conductor of length 1 m is placed in a uniform magnetic field of 5 xx 10^-4 Wb/ m^2 at an angle of 60^@ with the field. If the magnetic force on the conductor is 3 xx 10^-3 N , calculate the current in the conductor.