Question

In an SHM, kinetic and potential energies become equal when the displacement is 1/$\sqrt{2}$ times the amplitude. In SHM, kinetic energy is zero when potential energy is maximum.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

If both assertion and reason are true but reason is not the correct explanation of assertion

Answer 2

When the displacement of a particle executing SHM is $y$, then its $K . E .=\frac{1}{2} m \omega^{2}\left(a^{2}-y^{2}\right)$ and $P . E .=\frac{1}{2} m \omega^{2} y^{2}$ For $K E=P: \sigma$ or $2 y^{2}=a^{2}$ or, $y=a / \sqrt{2}$. Since total energy. remains constant through out the motion, which is $l=k . E .+P . E .$ So, when $P E$ is maximum then $K . E .$ is zero and vice versa.