Question

Assertion : Moon has no atmosphere.
Reason : The escape velocity for moon is less than that for earth.

• 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: (A)

The escape velocity for earth is $11.2km{s}^{-1}$. The escape velocity for moon is $2.3km{s}^{-1}$. Gas molecules if formed on the surface of the moon have velocities larger than this and will escape the gravitational pull of the moon.