Question

A South pole and North pole of each strength ‘m’ are placed at the two corners of an equilateral triangle of side ‘a’. The resultant magnetic induction field strength at the third vertex is :

• A. 0 (zero)
• B. $\frac{2{\mu }_0}{4\pi }\frac{m}{d^2}$
• C. $\frac{{\mu }_0}{4\pi }\frac{m}{d^2}$
• D. $\frac{3{\mu }_0}{4\pi }\frac{m}{d^2}$

Answer 1

Answer: (C)

$\frac{{\mu }_0}{4\pi }\frac{m}{d^2}$

Field strength $=\frac{F}{m}$

Where m is a text pole of pole strength m.

$s_1=\frac{{\mu }_{0}m}{4\pi d^2},s_2=\frac{{\mu }_{0}m}{4\pi d^2}$

$gnet=\sqrt{s_1^2+s_2^2+2s_1{s}_{2}cos120}$

$=\frac{{\mu }_{0}m}{4\pi d^2}$