OnlineCBT
Physics · PYQ NEET UG 2019(1)
हिन्दीTwo point charges A and B, having charges \( +Q \) and \( -Q \) respectively, are placed at certain distance apart and force acting between them is \( F \). If \( 25\% \) charge of A is transferred to B, then force between the charges becomes:
Correct answer · Option 4
\( \frac{9F}{16} \)
Explanation
Initial force \( F = k\frac{Q^2}{r^2} \). New charges are \( q_1 = Q - 0.25Q = 0.75Q \) and \( q_2 = -Q + 0.25Q = -0.75Q \). New force \( F' = k\frac{(0.75Q)^2}{r^2} = \frac{9}{16}F \).
