# Important Questions for Class 11 Chapter 14 - Oscillations

Important questions based on NCERT syllabus for Chapter 14 - Oscillations:

Question-1: Among the four x-t plots for linear motion of a particle, identify the graphs that represent a periodic motion. Also, find the find the period of motion if it is periodic.

Solution:
(a) It is non-periodic. As motion is not repeated.
(b) As the motion is repeated every 2 seconds, it is a periodic motion. Period = 2s.
(c) Non-periodic as motion is repeated in one position only.
(d) As the motion is repeated every 2 seconds, it is a periodic motion. Period = 2s.

Question-2: What is periodic motion? GIve example.

Solution: The motion that repeats itself at regular intervals of time is called periodic motion.E.g.: The motion of leaves and branches of a tree in breeze,orbital motion of planets in the solar system, oscillations of loaded spring, movement of the pendulum of a clock.

Question-3: What are damped oscillations? Give example.

Solution: The oscillations of a simple pendulum (or any other oscillating particle) are opposed by air drag and friction at its support. As a resultpendulum makes oscillations with decreasing amplitude. Such oscillations are called damped oscillations. E.g.: The oscillations of a pendulum, the oscillations of loaded spring, oscillations of the prongs of a tuning fork, etc..