question_answer

Direction of magnetic field at equatorial point is

A)  parallel to M                             

B)  perpendicular to M

C)  making an angle of \[{{45}^{o}}\]with M            

D)  anti-parallel to M

Correct Answer: A

Solution :

 Magnetic field due to a magnet at any point or equatorial line is given by \[B=\frac{{{\mu }_{0}}\,}{4\pi }\,\frac{M}{{{d}^{3}}}\] Direction of B is shown in figure. Hence, in equatorial position, the direction of magnetic field is parallel to magnetic axis direction is from North Pole to south pole i.e., parallel to M. We can also think about a tangent on magnetic induction curve from North Pole of a magnet to the south pole of same magnet as shown in figure.