question_answer

A neutral point is obtained at the centre of a vertical circular coil carrying current. The angle between the plane of the coil and the magnetic meridian is                                                 [SCRA 1998]

A)    0                                        

B)    45°

C)    60°                                    

D)    90°

Correct Answer: D

Solution :

   Magnetic meridian is a vertical N-S plane, the earth?s magnetic field \[({{B}_{H}})\] lies in it. (For more details see magnetism).                                               To obtain neutral point at the centre of coil, magnetic field due to current  and \[{{B}_{H}}\] must cancel each other. Hence plane of the coil and magnetic meridian must be perpendicular to each other as shown