A thin liquid film of thickness ` 5 xx 10^(-5)` m is formed between two glass plates of surface area ` 1 xx 10^(-2) m^(2)` , If the surface tension of the liquid is ` 60 xx 10^(-2)` n/m the force that is required to separate the glass plates is

Options

A. 240 N
B. 120 N
C. 24 N
D. 1.2 N

Answer

A

Explanation

AT = Fd
`F = (2AT)/d = (2 xx 10^(-2) m^(2) xx 60 xx 10^(-2)N//m)/(5xx10^(-5))`
` = (2xx 60)/5 xx10`
= 240 N