CBSE Class 12 · 2003 · Magnetic Properties of MatterVery Short Answer

Write the S.I. unit of
(i) magnetic pole strength,
(ii) magnetic dipole moment of a bar magnet.

Answer: (i) ampere-metre (A m);
(ii) ampere-metre $^{2}$ (A m $^{2}$ ).

Solution

Pole strength

m

is defined through

F = m B

, so its unit is

\frac{newton}{tesla} = A m

.
Magnetic dipole moment

M = m \times 2 l

(pole strength times magnetic length), giving the unit A m

\times

=

A m

^{2}

m : A m M : A m^{2}

CBSE Class 12 Board · 2003 · Subjective