Question

Find the magnetic field intensity at the centre O of a square of the sides equal to 5m and carrying 10A of current.

(a) 1.2

(b) 1

(c) 1.6

(d) 1.8

This question was addressed to me by my school principal while I was bunking the class.

This key question is from Biot Savart Law in portion Magnetostics of Electromagnetic Theory

Answer 1

Correct answer is (d) 1.8

The best explanation: The magnetic field is given by H = 4I/√2πω. Put I = 10 and ω = 5m. Thus H = 4 x 10/√2π(5) = 1.8 unit.