Question

what is torque??and it's sI unit

Answer 1

Units. ... The unit newton metre is properly denoted N⋅m or N m. This avoids ambiguity with mN, millinewtons. The SI unit for energy or work is the joule. It is dimensionally equivalent to a force of one newton acting over a distance of one metre, but it is not used for torque.

Answer 2

A force that tends to cause rotation is called torque.
And its si unit is Newton metre.