Question

What torque acts on a 50 turn coil of 200 cm^2 area carrying a current of 20 A held with its axis at right angles to a uniform magnetic field of 0.2T?

(a) 8 Nm

(b) 0.8 Nm

(c) 4 Nm

(d) 0.8 Nm

The question was posed to me by my school principal while I was bunking the class.

I want to ask this question from Torque on Current Loop & Magnetic Dipole topic in chapter Moving Charges and Magnetism of Physics – Class 12

Answer 1

Right option is (c) 4 Nm

Explanation: Torque = NIBA sinθ.

Torque = 50 × 20 × 0.2 × 200 × 10^-4 × sin (90)

Torque = 4Nm.