Ans. The characteristics of SHM are:
(i) A body executing SHM always vibrates about a fixed position.
(ii) The acceleration of a body executing SHM is 'always directed towards the mean position.
(iii) The magnitude of acceleration is always directly proportional to its displacement from the mean position i.e., acceleration will be zero at the mean position while it will be maximum at the extreme positions.
(iv) The velocity of a body executing SHM is maximum at the mean position and zero on the extreme positions.