A bar magnet of length 6 cm has a magnetic moment of 4 J T–1. Find the strength of magnetic field at a distance of 200 cm from the centre of the magnet along its equatorial line.
(a) 4 × 10–8 tesla
(b) 3.5 × 10–8 tesla
(c) 5 × 10–8 tesla
(d) 3 × 10–8 tesla
Correct option: c) 5 × 10–8 tesla
Explanation:
Along the equatorial line, magnetic field strength
Solving we get, B = 5 × 10–8 tesla
