Question

Which component of a force does not contribute towards torque?

Answer 1

We know that
$$\begin{gathered} \overrightarrow{\tau }=\overrightarrow{r}\times \overrightarrow{F} \\ \Rightarrow \tau =rF\sin \theta \end{gathered}$$
Therefore, Force, F having component parallel to r will not contribute to torque because in that case $\sin \theta =\sin 0^0=0$