If `vecF` is the force acting on a particle having position vector `vecr and vectau` be the torque of this force about the region, then :

Options

A. `vecr.vectaugt0 and vecF.vectault0`
B. `vecr.vectau=0 and vecF.vectau=0`
C. `vecr.vectau=0 and vecF.vectaune0`
D. `vecr.vectaune0 and vecF.vectau=0`

Answer

B

Explanation

`vecr and vecF` are in the same plane, while `vectau` is perpendicular to the plane form by `vecr and vecF` Hence, dot product of `vecr and vecF` of `vectau` (solar produce) is always zero