Question

Assertion : The energy of X-ray photon is greater than that of light (visible) photon.
Reason : X-ray photon in vacuum travels faster than light photon.

• 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: (C)

Energy of a photon $E=\frac{hc}{\lambda}$. As $\lambda$ for X-ray is smaller than light, so energy of X-rays is greater than that of light. Therefore, assertion is true. Here, reason is false as X-rays and light travel with same speed in vacuum.