Question

7. Determine the magnetic field of a bar magnet of length
10 cm, having a moment of 0.5 A. m2, on the axis at a
point 20 cm away from the mid-point of the magnet.
(1.42 x 10-51]​

Answer 1

The magnetic field of a bar magnet will be 1.42 × 10^-5 T

Explanation:

The magnitude of bar magnet can be found by using following formula

B = 10^-7 2Mr/(r^2 – l^2)^2               ………… (i)

in the question it is given that

M = 0.5 Am^2

r = 20 cm

length of magnet = 2l = 10 cm

so,  l= 5 cm

By putting values in equation i we get,

B = 1.42 × 10^-5 T