Question

The magnetic field due to a small magnetic dipole of magnetic moment $M$ at distance $r$ from the centre on the equatorial line is given by (in M.K.S. system)

• A. $\frac{\mu_{0}}{4 \pi} \times \frac{M}{r^{2}}$
• B. $\frac{\mu_{0}}{4 \pi} \times \frac{M}{r^{3}}$
• C. $\frac{\mu_{0}}{4 \pi} \times \frac{2 M}{r^{2}}$
• D. $\frac{\mu_{0}}{4 \pi} \times \frac{2 M}{r^{3}}$

Answer 1

Answer: (B)

$B_{\text {equatorial }}=\frac{\mu_{0}}{4 \pi} \frac{M}{r^{3}}$