Abrick is resting on a rough incline as shown in the figure. the friction force acting on the brick, along the incline, is
a) zero.
b) equal to the gravitational force of the brick.
c) greater than the gravitational force of the brick.
d) less than the gravitational force of the brick.

D) less than the gravitational force of the brick.

Explanation:

When a brick is at rest on the inclined plane

then we will have all forces balanced on the brick

so we will have force balance along the inclined plane given as

on the other side we can find force balance perpendicular to the inclined plane

so from above equation we can say that friction force is the component of the weight of the object along the inclined plane

so correct answer is

D) less than the gravitational force of the brick.