A block of mass m is at rest under the action of force F against a wall as shown in figure. Which of the following statement is incorrect?

Options

A. `f=mg`[where `f` is the friction force]
B. `F=N` [where `N` is the normal force]
C. `F` will not produce torque
D. `N ` will not produce torque

Answer

D

Explanation

The cubical block is in euqilibrium for translational equilibrim.

a. `SigmaF_(x)=0impliesF=N`
b. `SigmaF_(v)=0impliesf=mg`
`Sigmatau_(c)=0` where `tau_(C)=`torque about `CM C`
Torque is created by frictional force (`f`) about `C=fxxa` in a clockwise direction. There should be another torque which should counter this torque. The normal reaction `N` on the block acts as shown in figure. This will creat a torque `Nxxb` in the anticlockwise direction. Such that `fxxa=Nxxb`