Question

If \( m \) is magnetic moment and \( B \) is the magnetic field, then the torque is given by:

• A. \(\vec{m} \vec B \)
• B. \( \frac{\vec m}{\vec B} \)
• C. \(\vec m \times \vec B \)
• D. \( |\vec m||\vec B| \)

Hint:

Always use the cross product for torque calculations in magnetic fields.

Answer 1

The Correct Option is C

Step 1: The torque \( \tau \) experienced by a magnetic dipole in a uniform magnetic field is given by: \[ \tau = \vec {m} \times \vec{B} \] where \( \vec {m} \) is the magnetic moment and \( \vec {B} \) is the magnetic field. Step 2: The cross product indicates that the torque is perpendicular to both \(\vec m \) and \( \vec B \), leading to rotational motion.