Question

Force between two identical bar magnets whose centres are $r$ metre apart is $4.8\, N$ when their axes are in the same line. If separation is increased to $2\, r$, the force between them is reduced to

• A. 2.4 N
• B. 0.6 N
• C. 1.2 N
• D. 0.3 N

Answer 1

Answer: (D)

0.3 N

Answer 2

In magnetic dipole, Force ??1/r ? New force $=\frac{4.8}{2^{4}}=\frac{4.8}{16}=0.3$ N.