Question

The torque acting on a coil of N turns, area A and current I, placed at an angle θ to a uniform magnetic field B, is:

Options

• \[\tau = \frac{NIAB}{\sin\theta}\]

• \[\tau = NIB\sin\theta\]

• \[\tau = NIAB\sin\theta\]

• \[\tau = NIAB\cos\theta\]

Answer 1

The torque on a current-carrying coil in a uniform magnetic field is \[\tau = NIAB\sin\theta\]. It can also be written in vector form as \[\vec{\tau} = \vec{m} \times \vec{B}\], where \[\vec{m} = NI\vec{A}\] is the magnetic dipole moment.