Question 4: Give one practical example each of free and forced oscillation.
When an object is in free oscillation, it vibrates with its natural frequency without the interference of some external force. Such an oscillation of the body (or system) without the influence of external influence other than the cause (or force) which initiated it is called free oscillation.
Example of free oscillation
Oscillation of a simple pendulum is a good example of free oscillation. When a simple pendulum is set into oscillation, it vibrates with its own natural frequency. If it is not disturbed by some external force, it will continue to do so with its natural frequency.
If a force is continuously and repeatedly applied to keep the oscillation going, the oscillation is said to be forced oscillation.
Example of forced oscillation
If a child is swinging in a swing and someone is continuously providing pushes to the swing, then the appropriately timed pushes will keep the swing swinging. This is an example of forced oscillation.
Check your understanding
1. Natural frequency of a simple pendulum depends upon
|(a) mass of the bob||(b) Initial force applied||(c) square root of its length|
|(a) driven harmonic vibration||(b) damped harmonic vibration||(c) non of these|