question_answer

Direction for: In each of the following questions a statement of Assertion is given followed by a corresponding statement of Reason just below it. Of the statements mark the correct answer as

Assertion: Smaller drops of liquid n deforming forces better than the larger drop Reason: Excess pressure inside a drop directly proportional to its surface area.

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

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

C) If assertion is true but reason is false.

D) If both assertion and reason are false.

Correct Answer: C

Solution :

Also excess pressure inside a bubble is \[P=\frac{4T}{R}\] where R is radius of bubble. Since   excess   pressure   is   inversely proportional to radius, hence excess pressure inside a smaller drop is large as compared to larger drop due to which smaller drop resists deforming forces better than a larger drop Also      \[P=\frac{4T}{R}=\frac{4w}{R.\Delta A}\]      \[\left( \because T=\frac{W}{\Delta A} \right)\] \[\Rightarrow \]     \[P\propto \frac{1}{\Delta A}\] Hence, excess pressure is inversely proportional to surface area.