Statement I: A needle placed carefully on the surface of water may float, whereas the ball of the same material will always sink.
Statement II: The buoyancy of an object depends both on the material and shape of the object.

Options

A. both Assertion and Reason are true and the Reason in the correct explanation of the Assertion.
B. both Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
C. Assertion is true but the Reason is false.
D. both Assertion and Reason are false.

Answer

C

Explanation

A needle placed carefully on the surface of water may float due to surface tension, as upward force due to surface tension balances the weight of the needle. But thes upward forces due to surface tension are very small as compared to weight of ball, also the weight of liquid displaced by the ball immersed in liquid is less than the weight of the ball, hence ball sinks into the liquid. Here, Asssertion is true but Reason is false because bouyancy of an object depends on the weight of the liquid displaced by the immersed part of the object in liquid.