A thin liquid film formed between a U-shaped wire and a light slider supports a weight of `1.5xx10^(-2)N`. The length of the slider is 30 cm and its weight is negligible. The surface tension of the liquid film is:

Options

A. a) 0.0125 `Nm^(-1)`
B. b) 0.025 `Nm^(-1)`
C. c) 0.1 `Nm^(-1)`
D. d) 0.05 `Nm^(-1)`

Answer

B

Explanation

`{:("Force of"),("surface tension"):}}="weight on slider"`
`2Tl=W`
`therefore" "T=(W)/(2l)=(1.5xx10^(-2)N)/(2xx0.30m)`
`=0.025Nm^(-1)`