Question

"If two equal strength charges are
placed in air --- apart from each
other and if they exert a force of
on each other, then each charge is
said to be a unit charge or charge of 1
coulomb" *
O 1N,9 x 10-9 m
O 1m, 9 x 109 N
O im, 9 x 10-9 N
O 9 x 10-9 m, 1 N​

Answer 1

Answer:

1. 4)the answer 9 multiple 10 _9 m, 1n

Answer 2

The correct option is (ii) 1 m, 9 × 10⁹ N.

Explanation:

The Coulomb's law for the force of attraction between two charges is directly proportional to the product of the magnitude of the two charges supposedly at rest and inversely proportional to the square of the magnitude of the distance between the charges.

The force between the two charges $Q$ and $q$ supposedly separated by a distance of $R$ will be,

$F=\frac{1}{4\pi E_{o} } \frac{Qq}{R^{2} }$

If we consider the charges are unit charges that is $Q=q=1C$ and the separation between the charges is $1m$, the force will be

$F=\frac{9*10^{9}(1)(1) }{1^{2} }$

$F=9$ × $10^{9}N$

Hence, among all the given options, substituting the values of the option (ii), we get the force correctly as 9 × 10⁹ N.

Therefore, the statement can be re written as,

" If two equal strength charges are placed in air 1 meter apart from each other and if they exert a force of 9 × 10⁹ N on each other, the charge is said to be a unit charge or charge of 1 coulomb".