Question

What unit is torque measured in?

Answer 1

Hint: Torque is the measure of the twisting force which when applied to a body produces the sensation of rotation in the body. In other words, torque is to rotate what force is to motion. Torque is also known as the moment of a force. We shall study about torque in detail in the following section and then see, in what unit is torque measured.

Complete answer:
Let us understand torque with the help of the following diagram:

Here, the torque of the force F about the head of the vector r is given by:
$\Rightarrow \tau =\overrightarrow{r}\times \overrightarrow{F}$
Now, if we look at the formula of this torque, we can clearly see that it is a cross product of distance vector (which has a standard unit of meter) and Force (which is measured in Newton). Thus, the standard unit or one can say the SI of torque will be Newton-meter (N.m.) .
In SI base units, the unit of torque will be equal to $kg{{m}^{2}}{{s}^{-2}}$. Also, we can write the dimension of torque using this SI base unit as $\left[ M{{L}^{2}}{{T}^{-2}} \right]$.
Some other common and less used units of torque are pound-force-feet, lbf-inch, etc.
Hence, the standard unit in which torque is measured is Newton-meter (N.m.) .

Note:
The unit of any quantity be it force, momentum, acceleration, torque, mass, etc. is not a specific quantity. People around the globe use different unit systems. For example, the Europeans generally use the metric system while calculating mass of an object whereas the Americans use the CGS system. This is why a standard system was developed known as the SI system of units which is accepted all over the globe.