question_answer

Which of the following expressions corresponds to simple harmonic motion along a straight line, where x is the displacement and a, b, c are positive constants?                                                       [JEE ONLINE 12-04-2014]

A)  \[a+bx-c{{x}^{2}}\]  

B)       \[b{{x}^{2}}\]

C)  \[a-bx+c{{x}^{2}}\]  

D)       \[-bx\]

Correct Answer: D

Solution :

[d]

In linear S.H.M., the restoring force acting on particle should always be proportional to the displacement of the particle and directed towards the equilibrium position.

i.e.,  or  where b is a positive constant.