Question

A bar magnet of length 6 cm has a magnetic moment of 4JT^-1 Find the strength of magnetic field at a distance of 200 cm from the centre of the magnet along its equatorial line.

Options

• 4 × 10^-8 tesla

• 3.5 × 10^-8 tesla

• 5 × 10^-8 tesla

• 3 × 10^-8 tesla

Answer 1

5 × 10^-8 tesla

Explanation:

B_eq = `mu_0/(4pi)"M"/"d"^3`

= `10^-7xx4/3`

= 5 × 10^-8 T