A closely wound coil of 50 turns and radius 15 cm carries a current 3…

The correct answer is Option (3) → $10.59\, Am^2$

Given:

Number of turns, N = 50

Radius of coil, R = 15 cm = 0.15 m

Current, I = 3 A

Magnetic moment of a coil:

$\mu = N I A$, where $A = \pi R^2$

Calculate area:

$A = \pi R^2 = \pi (0.15)^2 = \pi \cdot 0.0225 \approx 0.0707\ \text{m}^2$

Magnetic moment:

$\mu = 50 \cdot 3 \cdot 0.0707 \approx 10.605\ \text{A·m²}$

Magnetic moment of the coil ≈ 10.61 A·m²