11. Assertion : Tiny drops of liquid resist deforming forces better than bigger drops. Reason : Excess pressure inside a drop is directly proportional to surface tension.

Read the assertion and reason carefully to mark the correct option out of the options given below:

(a)       If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b)       If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c)        If assertion is true but reason is false.

(d)       If the assertion and reason both are false.

(e)       If assertion is false but reason is true.

Ans. (b)          When a drop of liquid is poured on a glass plate, the shape of the drop is governed by two forces, the force of gravity. For very small drops, the potential energy due to gravity is insignificant compared to that due to surface tension. Hence, in this case the shape of the drop is determined by surface tension alone and drop becomes spherical.

(23)