Assertion: A compass needle when placed on the magnetic north pole of the earth rotates in vertical direction.
Reason: The earth has only horizontal component of its magnetic field at the north poles.

Options

A. Both A and Rare Tuę and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is true

Answer

D

Explanation

Magnetic needle can rotate in horizontal plane only. But at poles, there is no horizontal component of Earth.s magnetic field. So, the needle will remain horizontal and will point in any direction. Hence the assertion is false. At poles, Earth has only vertical components of its magnetic field. Hence, the reason is also false.