The dimensional formula for surface tension is given by which of the following?

Solution

1. Surface tension $S$ is defined as force per unit length, $S=F/L$.
2. The dimensions of force $F$ are $[ML{T}^{-2}]$.
3. The dimensions of length $L$ are $[L]$.
4. Dividing these gives $$\begin{array}{rl}S& =[ML{T}^{-2}]/[L]\\ & =[M{T}^{-2}]\end{array}$$.
5. Hence the answer is (C).