21. Which of the following statements about surface tension is true?
a) Surface tension decreases with increasing temperature
b) Surface tension increases with increasing temperature
c) Surface tension is independent of temperature
d) Surface tension is only applicable to liquids
22. The capillary rise of a liquid in a tube can be increased by:
a) Increasing the diameter of the tube
b) Increasing the angle of contact
c) Increasing the viscosity of the liquid
d) Increasing the temperature of the liquid
23. The phenomenon of capillary action is due to:
a) Cohesion between molecules of the liquid
b) Adhesion between molecules of the liquid and the tube
c) Both cohesion and adhesion
d) None of the above
24. The ability of a liquid to wet a solid surface depends on:
a) Surface tension
b) Adhesion
c) Cohesion
d) All of the above
25. The shape of a meniscus in a capillary tube is affected by:
a) Surface tension
b) Adhesion
c) Cohesion
d) All of the above
