Electric Charges and Field Problems - Numerical 01

Two identical balls, each of mass 0.1 x 10^-³ kg, carry identical charges and are suspended by two threads of equal length. At equilibrium, they position themselves as shown in the figure below. Calculate the charge on either ball.

Sub Topics

Suggested answer:

Suggested answer:

The ball on the left is in equilibrium under the action of following three forces:

(i) Tension T in the thread

(ii) Weight mg of the ball

(iii) Coulomb repulsion, F

Tension T can be resolved into two rectangular components -

T cos 60^o and T sin 60^o.

For equilibrium, F = T cos 60^o, mg = T sin 60^o

Dividing,

Substituting, we get

or q =10^-⁷ C = 0.1 mC