Concepts Of Physics MCQ Edition [Volume 2]PhysicsPermanent Magnets

Let r denote the distance from the centre of a magnetic dipole to a point on its axis. The magnetic field at this point is proportional to

Options

A1 r^4
B1 r^3
C1 r
D1 r^2

Correct answer

B. 1 r^3

Step-by-step solution

The magnetic field at a distance r on the axis of a short magnetic dipole of magnetic moment M is given by B = ₀ 4 2M r^3 Therefore, the magnetic field is inversely proportional to the cube of the distance from the centre of the dipole. B 1 r^3

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