A thin film of a liquid is maintained between two very long, thin, parallel, horizontal wires separated by a distance 2a. A long wire of mass per unit length `lamda` is gently placed over the liquid film at the middle parallel to the wires. As a result the liquid surface is depressed by a vertical distance `y(yltlta)` at equilibrium. The surface tension of the liquid is `(lamdaga)/(ky)` then k is

Answer

2

Explanation

`W=lamdalg'2Tloctheta=W=alphalg`
`tau=(lamdag)/(2costheta)` where `costheta=(y)/(sqrt(a^(2)+y^(2)))=(y)/(a)`