Question

The mid points of two small magnetic dipoles of length d in end-on positions, are separated by a distance x, (x > > d). The force between them is proportional to x^–n where n is:

(a) 1 

(b) 2 

(c) 3 

(d) 4

Answer 1

Correct option: (d) 4

Explanation:

In magnetic dipole

In the given question, 

Force µ x^{– n} 

Hence, n = 4