Question

force between identical spheres charged with same charge is F. if 50% of one sphere is transferred to the other then new force will be.
a)3/4F. b)3/8F​

Answer 1

$\bold {\huge {Answer :-}}$

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We know that the Force between two object is given by

$\Large\bold{\boxed{\boxed{F = \frac{K. q_1.q_2}{r^2}}}}$

→Here r is distance b/w the objects

⇨ Since, both spares are identical

Therefore, q1 = q2 = q

$\Large\bold{\boxed{\boxed{\therefore \:F = \frac{K. q^2}{r^2}}}}$

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Now, If 50% of the charge of one sphere is transferred to another, then the force between the two spheres becomes,

Finally,

Charge of sphere 1 = q/2 C

Charge of sphere 2 = q + q/2 = 3q/2 C

$\Large\bold{\therefore \:F' = \frac{K. (q/2).(3q/2)}{r^2}}$

On solving

$\Large\bold{\therefore \:F' = \frac{3}{4}\frac{K. q^2}{r^2}}$

$\Large\bold{\therefore \:F' = \frac{3}{4}. F}$

→option (a)