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 `2r`, the force between them is reduced to

Options

A. `4N`
B. `2N`
C. `1N`
D. `0.5N`

Answer

d

Explanation

(d) As `F prop (1)/(4)` and r becomes twice, therefore, F becomes
`(1)/(2^(4))=(1)/(16)` times `therefore (1)/(16)xx8=0.5N`.