Two charges 8 C and -6 C are placed at a distance of separation between them and exerts a force of magnitude F on each other. If a charge 8 C is added to each of these and they are brought nearer to by a distance d/3, the magnitude of force between them will be

Options

A. `F/3`
B. `9F/4`
C. 6 F
D. `2 F/3`

Answer

( c)

Explanation

Initial Force,
`F_(1) = Kq_(1)q_(2)/d^(2) = K(8)(-6)/d^(2) = k(-48)/d^(2)`
Final force
`F_(2) = kq_(1)q_(2)/(d/3)^(2) = k(16)(2)/d^(2)/9 = k 288/d^(2)`
`rArr F_(2)/F_(1) = 288/48 = 6`
`F_(2) = 6F_(1)`