Assertion : If the earth suddenly comtracts , the duration of day will decreases
Reason : The angular velocity of the earth's rotation will decrease

Options

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

Answer

C

Explanation

When the earth contracts its moment of inertia decrease Therefore from the relation
`1 omega = L`
or `Iomega` constant
with decrease of moment of inertia velocity of earth increase Thus period `T =- (2pi)/(omega)` will decrease. Hence duration of the day will decrease.