Consider a wire carrying a steady current, I placed in a uniform magnetic field `vecB` perpendicular to its length. Consider the charges inside the wire. It is known that magnetic forces do not work. This implies that

Options

A. Motion of charges inside the cnductor is unaffected by B, since they do not aborb energy
B. some charges inside the wire move to the surface as a result of B
C. if the wire moves under the influence of B, no work is done by the force.
D. If the wire moves under the influence of B, no work is done by the magnetic force on the ions, assumed fixed within the wire.

Answer

B, D

Explanation

Magnetic forces on a wire carrying a steady current, I placed in a uniform magnetic field B, a wire carrying a steady current, I placed in a uniform magnetic field Bf perpendicualr to its length is given by
`F=IlB`
the direction force is given by Fleming's left had rule and F is perpendicular to the direction of magnetic field B. Therefore, work done b the magnetic force on the ions is zero.