Question

Rectangular loop of side $a$ and carrying current $I$ is placed perpendicular to magnetic field. What will be the magnetic moment?

• A. \( I a^2 \)
• B. \( I a^3 \)
• C. \( I a \)
• D. \( I a^2 \hat{k} \)

Hint:

The magnetic moment is directly proportional to the current and the area of the loop. For a square loop, the area is \( a^2 \).

Answer 1

The Correct Option is A

The magnetic moment \( \mu \) of a current-carrying loop is given by the formula: \[ \mu = I A \] where: - \( I \) is the current, - \( A \) is the area of the loop. For a rectangular loop with side lengths \( a \) and \( a \), the area of the loop is: \[ A = a^2 \]
Thus, the magnetic moment of the loop is: \[ \mu = I \times a^2 \] Therefore, the correct answer is \( I a^2 \).