• # question_answer Two identical short bar magnets each having magnetic moment M are placed at a distance of 2d with their axes -L to each other in a horizontal plane. The magnetic induction at a point midway between them is- A) $\frac{{{\mu }_{0}}}{4\pi }\sqrt{2}\,\frac{M}{{{d}^{3}}}$                 B) $\frac{{{\mu }_{0}}}{4\pi }(\sqrt{3})\,\frac{M}{{{d}^{3}}}$C) $\left( \frac{2{{\mu }_{0}}}{4\pi } \right)\,\frac{M}{{{d}^{3}}}$                      D) $\frac{{{\mu }_{0}}}{4\pi }(\sqrt{5})\,\frac{M}{{{d}^{3}}}$

$=\,\,\,\,\sqrt{{{\left( \frac{2kM}{{{d}^{3}}} \right)}^{2}}+{{\left( \frac{kM}{{{d}^{3}}} \right)}^{2}}}=\frac{kM}{{{d}^{3}}}\,(\sqrt{5})$