Question

The magnitude of electrostatic force between two point charges, separated by a distance r is F. If the distance between the charges is doubled, then the new electrostatic force will be​

Answer 1

Answer:

Explanation:

Electrostatic force is inversely proportional to square of distance between charges.

As it will be doubled the force will be one forth of previous value

i.e F/4

Answer 2

Answer:

When two same charges q are at a distance r and the force between them is F. If we change the distance to 2r the force will be ​ $F_{old} /4$

Explanation:

• The force acting between stationary charges is called electrostatic force

• The coulomb's law gives the magnitude of the force as

        $F=\frac{Kq_{1} q_{2} }{r^{2} }$

        where  $K=9*10^{9}$

        $q_{1} , q_{2}$ - the charges

        $r$- the distance between the charges

From the question, we have given that

let the charge be $q$

the distance between the charges is  $r$

the amount of force is $F_{old} =\frac{Kq_{1} q_{2} }{r^{2} }$

now the distance is doubled

$r'=2r$

the new force is $F_{new} =\frac{Kq_{1} q_{2} }{r'^{2} }=\frac{Kq_{1} q_{2} }{4r^{2} }=F_{old} /4$