Question

A block of mass `m` is held fixed against a wall by a applying a horizontal force `F`. Which of the following option is incorrect :
.
A. friction force = mg
B. `F` will not produce torque
C. normal will not produce torque
D. normal reaction = F

Answer 1

Correct Answer - C
This is the equilibrium of coplanar forces. Hence,
`sum F_(x) = 0`
:. `F = N`
:, `sum F_(y) = 0`
`f = mg`
`sum tau_(C) = 0`
:. `vec tau_(N) + vec tau_(f) = 0`
:. Since `vec tau_(f) ne 0` :. `vec tau_(N) ne 0`
:. Correct Answer is `(C)`.