Question

If an electron moves with a velocity \( v \) in a magnetic field \( B \), the magnetic force on the electron is maximum when the angle between \( v \) and \( B \) is

• A. 30°
• B. 180°
• C. 60°
• D. 90°
• E. 0°

Hint:

For maximum magnetic force on a moving particle, the angle between the velocity vector and the magnetic field should be \( 90^\circ \).

Answer 1

The Correct Option is D

The magnetic force \( F \) on a charged particle moving in a magnetic field is given by the equation: \[ F = q v B \sin \theta \] Where: - \( q \) is the charge of the particle - \( v \) is the velocity of the particle - \( B \) is the magnetic field - \( \theta \) is the angle between the velocity vector and the magnetic field vector. For the magnetic force to be maximum, \( \sin \theta \) must be maximum. The maximum value of \( \sin \theta \) is 1, which occurs when \( \theta = 90^\circ \). Thus, the magnetic force is maximum when the angle between \( v \) and \( B \) is \( 90^\circ \). Hence, the correct answer is (D) 90°.