Q1: When there are no external forces, the shape of a liquid drop is determined by
a) Surface Tension of the liquid
b) The density of the liquid
c) The viscosity of the liquid
d) The temperature of air only
Answer: (a) Surface Tension of the liquid
Q2: If T is the surface tension of the soap solution, the amount of work done in blowing a soap bubble from diameter D to a diameter 2D is
a) 2πD2T
b) 4πD2T
c) 6πD2T
d) 8πD2T
Answer: (c) 6πD2T
Q3: If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of the container is
a) Acute angle
b) Obtuse angle
c) 900
d) 00
Answer: (d) 00
Q4: Raindrops are spherical in shape because of
a) Capillary
b) Surface Tension
c) Downward motion
d) Acceleration due to gravity
Answer: (b)Surface Tension
Q5: In a surface tension experiment with a capillary tube, the water rises up to 0.1m. If the same experiment is repeated on an artificial satellite which is revolving around the earth. The rise of water in a capillary tube is
a) 0.1 m
b) 9.8 m
c) 0.98 m
d) Full length of the capillary tube
Answer: (d) Full length of the capillary tube
Q6: At the critical temperature, the surface tension of the liquid
a) Is zero
b) Is infinity
c) Is the same as that at the other temperature
d) Cannot be determined
Answer: (a) Is zero
Q7: The surface of the water in contact with the glass wall is
a) Plane
b) Concave
c) Convex
d) Both a and b
Answer: (b) Concave
Q8: When a soap bubble is charged
a) It contracts
b) It expands
c) It does not undergo any change in size
d) None of these
Answer: (b) It expands
Q9: If common salt is dissolved in water, then the surface tension of saltwater is
a) Increased
b) Decreased
c) Not changed
d) First increases then decrease
Answer: (a) Increased
Q10: A drop of oil is placed on the surface of the water. Which of the following statements is correct?
a) It will remain on it as a sphere
b) It will spread as a thin layer
c) It will partly be as spherical droplets and partly as thin films
d) It will float at the distorted drop on the water surface.
Answer: (b) It will spread as a thin layer
