Question

Magnetic intensity for an axial point due to a short bar magnet of magnetic moment M is given by

• A. $\frac{{\mu }_0}{4\pi }\times \frac{M}{d^3}$
  
• B. $\frac{{\mu }_0}{4\pi }\times \frac{M}{d^2}$
  
• C. $\frac{{\mu }_0}{2\pi }\times \frac{M}{d^3}$
  
• D. $\frac{{\mu }_0}{2\pi }\times \frac{M}{d^2}$

Answer 1

The correct option is C $\frac{{\mu }_0}{2\pi }\times \frac{M}{d^3}$


$B_a=\frac{\mu )0}{4\pi }\frac{2M}{d^3}=\frac{{\mu }_0}{2\pi }\frac{M}{d^3}$