Class 11 Physics Mechanics Mechanical Properties of Fluids
Assertion :Tiny drops of liquid resist deforming forces better than bigger drops Reason :Excess pressure inside a drop is directly proportional to surface tension.
(a)
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
(b)
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
(c)
Assertion is correct but Reason is incorrect
(d)
Both Assertion and Reason are incorrect
Correct answer: (b)
Solution: 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.