When a current carrying loop is replaced by an equivalent magnetic dipole ........

Options

A. the distance l between the poles is fixed
B. the pole strength p of each pole is fixed
C. the dipole moment is reversed.
D. the product pl is fixed.

Answer

D

Explanation

Since a current carrying loop acts as a magnet and its magnetic dipole moment is `m=IA` where, I = current and A is the area of loop. If bar magnet of the same dipole is taking its magnetic dipole moment is,
`m= 2pl`,
`therefore m alpha pl`
`m alpha pl` Here m is constant so the product of pl is also constant.