Question

The magnetization of bar magnet of length 5 cm, cross-sectional area 2 cm² and net magnetic moment 1 Am² is ______.

विकल्प

• 3 × 10⁵ A/m

• 4 × 10⁵ A/m

• 2 × 10⁵ A/m

• 1 × 10⁵ A/m

Answer 1

The magnetization of bar magnet of length 5 cm, cross-sectional area 2 cm² and net magnetic moment 1 Am² is 1 × 10⁵ A/m.

Explanation:

Given, l = 5 cm = 5 × 10^-2 m,

a = 2 cm² = 2 × 10^-4 m²

and M = 1 Am^-2

The magnetisation of the bar magnet is given by

I = `"M"/"V"`

where, V = volume of bar magnet = a × I

`=> "l" = "M"/("a" xx "l")`

Substituting given values, we get

l = `1/(2 xx 10^-4 xx 5 xx 10^-2) = 1/(10^-5)`

= 1 × 10⁵ A/m