Question

The magnetic potential due to a magnetic dipole at a point on its axis distance 40 cm from its center is found $2.4\times {10}^{-5}{JA}^1{M}^{-1}$ .The magnetic moment of the dipole will be

• A. 28.6${Am}^2$
• B. 32.2${Am}^2$
• C. 38.4${Am}^2$
• D. None of these

Answer 1

The correct option is C 38.4${Am}^2$

Given: Magnetic potential due to dipole=$2.4\times {10}^{-5}J{A}^{-1}{M}^{-1}$

Distance from the axis= 40 cm = 0.4m

Solution: As we know, the magnetic potential due to magnetic dipole is given by,

$V=\frac{{\mu }_{0}M\cos \theta }{4\pi r^2}$

On substituting the values we get,

$2.4\times {10}^{-5}=\frac{4\pi \times {10}^{-7}\times M}{4\pi (0.4{)}^2}$

On solving we get,

M=$38.4A{m}^2$

Hence, the correct option is (C).