Consider a wire carrying a steady current, I placed in a uniform magnetic field B perpendicular to its length. Consider the charges inside the wire. It is known that magnetic forces do no work. This implies that,

Question

Philoid · Accepted Answer

We know that the force due to magnetic field on moving charge is given by F= qvBsinθ where,

q is charge of the particle;

v is velocity of the charged particle;

B is magnetic field vector;

Θ is angle between V and B.

So, due to this force some charges inside the wire will come on the surface of the wire.

And, we know that magnetic force is not capable of doing work as it can change only direction of the of motion of charged particle. This change in direction of motion of charges allow the charges to create their own magnetic field and this keep the net magnetic force within the wire fixed.

Hence, our answers are option (b) and (d).