Assertion: The length of the day is slowly increasing.
Reason: The dominant effect causing a slowdown in the rotation of the earth is the gravitational pull of other planets in the solar system.

Options

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

Answer

C

Explanation

Angular speed of the earth is given by
`omega=(2pi)/T`
hence, length of day `(T)` depends upon angular speed `(omega)` of the earth, about its own axis.
Also Kepler's second law of motion which is also law of conservation of angular momentum holds true for sun-earth system. Hence, earth's rotation is not slowing down.