Question

A wire of length 1.2 m carrying a current of 4 A, when placed in a uniform magnetic field 5 T experiences a force of 12 N. Then the angle between the direction of current and magnetic field is

• A. \(30^\circ\)
• B. \(45^\circ\)
• C. \(60^\circ\)
• D. \(0^\circ\)
• E. \(90^\circ\)

Hint:

Maximum force when current is perpendicular to magnetic field.

Answer 1

The Correct Option is A

Concept: \[ F = BIL\sin\theta \]

Step 1: Substitute values.
\[ 12 = 5 \times 4 \times 1.2 \times \sin\theta \] \[ 12 = 24 \sin\theta \Rightarrow \sin\theta = \frac{1}{2} \]

Step 2: Find angle.
\[ \theta = 30^\circ \]