Question

A bar magnet having length 5 cm and area of cross-section 4cm² has magnetic moment 2Am². If magnetic susceptibility is 5 x 10^-6, the magnetic intensity will be ____________.

Options

• `0.2 xx 10^10 "A"/"m"`

• `5 xx 10^10 "A"/"m"`

• `2 xx 10^10 "A"/"m"`

• `0.5 xx 10^10 "A"/"m"`

Answer 1

A bar magnet having length 5 cm and area of cross-section 4cm² has magnetic moment 2Am². If magnetic susceptibility is 5 x 10^-6, the magnetic intensity will be `2 xx 10^10 "A"/"m"`.

Explanation:

`"Volume of the magnet V" = varphi xx "A"`

`= 5  "cm" xx 4  "cm"^2`

` = 20  "cm"^2`

`= 20 xx 10^-6 "m"^3`

`= 2 xx 10^-5 "m"^3`

magnetic moment = 2 Am²

`therefore "Magnetization" = (2 xx 10^-5)/2 = 10^-5 "A"//"m"`

`"Magnetic intensity H" = "M"/chi = 10^-5/(5 xx 10^-6)`

`= 2 xx 10^10  "A"//"m"`