25.(c) A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, what is the average force on each electron in the coil due to the magnetic field?
(The coil is made of copper wire of cross-sectional area , and the free electron density in copper is given to be about .)
The average force on each electron in the coil due to the magnetic field will be eVdB where Vd is the drift velocity of the electrons.
The current is given by
where n is the free electron density and A is the cross-sectional area.
The average force on each electron is