Question

Which figure represents the correct F.B.D of rod of mass m as shown in the figure?
 

(A)
 

(B)
 

(C)

(D) None of these

Answer 1

Hint
Firstly, we should observe the figure. We know how a normal reaction is directed on the rope. The tension along the rope always acts along the rope. After observing all the diagrams, we will be able to choose the correct options.

Complete step by step answer
From the given figure we get to know that the rod of mass is tilted with respect to the smooth surface.
We know that the normal reaction of the substance should be in the perpendicular direction to the surface of contact.
Gravitational force always acts in the downward direction.
The tension acts always along the rope.
So, the first figure satisfies all the conditions.
In this figure the tension is a long string or rope and it is away from the body.
The rod of mass is tilted and the normal reaction is at perpendicular to the body.
Hence the required solution is (A).

Note
One may think why option- ‘B’ is not correct because the normal reaction must be perpendicular to the rod. Option ‘C’ will also not be correct because the tension should be along the string. Option ‘A’ satisfies all the conditions. That’s why option ‘A’ is correct.