Question

Two point charge of +2uc and +6uc repel each other with a force of 12N. If

each is given an additional charge of -4uc, what will be the force?​

Answer 1

Answer:

The new force will be -4N

Explanation:

Given:

q₁ = +2μC

q₂ = +6μC

F = 12N

To find:

F' = ?

We know that,

$F=\frac{1}{4 \pi \epsilon} \frac{q_{1} q_{2} }{r^{2} }$

or, F ∝ q₁ q₂ ------(i)

A/Q, the new charges are,

q₁' = (+2 - 4)μC = -2μC

q₂' = (+6 - 4)μC = +2μC

Let the new force be F'

and, F' ∝ q₁' q₂' -------(ii)

From (i) and (ii), we have,

$\frac{F}{F'} = \frac{q_{1} q_{2} }{q'_{1} q'_{2} }$

⇒ $\frac{12}{F'} = \frac{(+2) (+6)}{(-2)(+2)}$

⇒ F' = -4 N