Question 4: Differentiate between free and forced oscillations.ANSWER
A body is executing free oscillation, if it oscillates with its natural frequency without any interference of any external force.
When a pendulum is disturbed a little and then left it will oscillate with its free natural frequency.
If a freely oscillating system is subjected to an external force, then the forced vibration will take place. The frequency of such oscillation will be the frequency of the applied force. Such oscillation is called forced oscillation.