# 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)