Question

A circular flat coil that has N turns, encloses an area A, and carries a current i has its central axis parallel to a uniform magnetic field B in which it is immersed.
The net torque on the coil is ____.


a) iBA

b) NiA

c) NiB

d) NiAB

e) Zero

Answer 1

Answer:

Torque on the coil will be ZERO

Explanation:

As we know that the magnetic moment of the closed current carrying coil is always along its axis and it is given as

$M = N i A$

now we know that magnetic field is also along the axis of the coil so here as we know the equation of torque given as

$\tau = \vec M \times \vec B$

so we have

$\tau = M B sin0$

$\tau = 0$