Answer:
The set up will not return to its original position once the applied force is removed
Step-by-step explanation:
An unstable equilibrium is a type of equilibrium in which the set up does not return to its original position once the applied force is removed.
The way the set up in the diagram is arranged, if there is any slight disturbance which removes the applied force, the metre rule will tilt towards the right and remain that way. This is because of the presence of the weight on the right side of the metre rule. This, therefore, makes the set up unstable.