Question

The dimension of torque is:

• A. $\left[M{L}^3{T}^{-3}\right]$
• B. $\left[M{L}^{-1}{T}^{-1}\right]$
• C. $\left[M{L}^2{T}^{-2}\right]$
• D. $\left[M{T}^{-2}\right]$

Answer 1

Answer: (C)

The moment of a force or the torque about an axis of rotation is equal to the product of the magnitude of the force $(F)$ and the perpendicular distance $(r)$ of the line of action of force from the axis of rotation.
$\therefore \tau =F\times r$
$\therefore \text{ Dimensions of torque }=\text{ Dimensions of force }\times \text{ Dimensions of distance }$
$=\left[ML{T}^{-2}\right]\times [L]=\left[M{L}^2{T}^{-2}\right]$