Question
Question: The magnetic field at a point X on the axis of a small bar magnet is equal to the field at a point Y...
The magnetic field at a point X on the axis of a small bar magnet is equal to the field at a point Y on the equator of the same magnet. The ratio of the distance of X and Y from the centre of the magnet is
A
2−3
B
2−1/3
C
23
D
21/3
Answer
21/3
Explanation
Solution
Suppose distances of points X and Y from magnet are x and y respectively then According to question Baxial =Bequatorial
⇒ 4πμ0⋅x32M=4πμ0⋅y3M⇒yx=121/3