Physics - Fluid Question with Solution | TestHub

When a wire is placed on the surface of a liquid and pulled up, the surface tension acts on both sides of the wire along its entire length.

The total downward force due to surface tension is given by:
$F=T\times 2L$

Given:
Force required to keep it in equilibrium, $F=0.04$ N
Length of the wire, $L=20$ cm $=0.2$ m

Substituting the given values into the formula:
$0.04=T\times 2\times 0.2$

$0.04=T\times 0.4$

$T=\frac{0.04}{0.4}=0.1$ N/m

Answer: $0.1$ N/m