Four point charges

PHYSICS · Subjective · CBSE · Physics · Units and Measurements · Units and Measurements

Problem

Four point charges, each of

+q

, are rigidly fixed at the four corners of a square planar soap film of side 'a'. The surface tension of the soap film is

\gamma

. The system of charges and planar film are in equilibrium, and

a = k \left[ \frac{q^2}{\gamma} \right]^{1/N}

, where 'k' is a constant. Then N is [2011]