Question

Statement I : Statement I: A horizontal force $F$ is applied such that the block remains stationary because $N$ will produce torque
Statement II : The torque produced by friction force is equal and opposite the torque produce due to normal reaction (N).

• A. If both statement I and statement II are true and statement II is the correct explanation of statement I.
• B. If both statement I and statement II are true but statement II is not the correct explanation of statement I.
• C. If statement I is true but statement II is false.
• D. If both statement I and statement II are false.

Answer 1

Answer: (A)

As the block remains stationary
$\Sigma f x=0 \text { i.e., } F=N $
$\Sigma f y=0 \text { i.e., } f=m g$
and $\Sigma \tau=0$ i.e., $\therefore \vec{\tau}_{f}+\vec{\tau}_{N}=0$

As $\vec{\tau}_{f} \neq 0 \therefore \vec{\tau}_{N} \neq 0$ and torque by friction and normal
reaction will be in opposite.