A particle of mass $m$ attached to an inextensible light string is moving in a vertical circle of radius $r$. The critical velocity at the highest point is $v_o$ to complete the vertical circle. The tension in the string when it becomes horizontal is

Surface tension of a liquid is due to:

Surface tension is due to 

A man is sitting in a boat which is floating in a pond. If the man drinks some water from the pond, water level in the pond decreases.

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

Name the force responsible for surface tension.

If a mosquito is dipped into water and released, it is not able to fly till it is dry again. Explain.

(A) The surface tension may be assumed to be a result of force between dipoles which oppose penetration of the liquid.
(B) The surface tension is a result of cohesive force which is mechanical, not electrical.

Assertion :Droplets of liquid are usually more spherical in shape than large drops of the same liquid.
Reason :Force of surface tension predominates the force of gravity in case of small drops.