Let F  be the force acting on a particle having position vector r  and T  be the torque of this force about the origin. Then

Q: Let $\vec{F}$  be the force acting on a particle having position vector $\vec{r}$   and $\vec{T}$  be the torque of this force about the origin. Then

(a) $ \vec{r} . \vec{T} = 0 $ and $ \vec{F} . \vec{T} = 0 $

(b) $ \vec{r} . \vec{T} = 0 $ and $ \vec{F} . \vec{T} \ne 0 $

(c) $ \vec{r} . \vec{T} \ne 0 $ and $ \vec{F} . \vec{T} = 0 $

(d) $ \vec{r} . \vec{T} \ne 0 $ and $ \vec{F} . \vec{T} \ne 0 $

Ans: (a)