Surface Tension & Capillary Action
1. Capillary action is a result of:
a) Gravitational pull
b) Viscosity
c) Surface tension
d) Radiation
Answer: c
2. The rise of oil in a wick is due to:
a) Oil’s density
b) Oil’s viscosity
c) Surface tension of oil
d) Oil’s pressure
Answer: c
3. A soap bubble takes a spherical shape due to:
a) Inertia
b) Pressure
c) Surface tension
d) Viscosity
Answer: c
4. A ball pen works on the principle of:
a) Viscosity
b) Boyle’s law
c) Gravitational force
d) Surface tension
Answer: d
5. Rainwater drops become spherical while falling due to:
a) Viscosity
b) Surface tension
c) Atmospheric pressure
d) Gravity
Answer: b
6. Water drops do not stick to an oily surface because of:
a) Lack of adhesive force
b) Surface tension
c) Immiscibility
d) Water being lighter than oil
Answer: b
7. An oil drop spreads over water because:
a) Oil is lighter than water
b) Oil is more viscous
c) Oil and water don’t mix
d) Surface tension of oil is lower than that of water
Answer: d
8. Hair of a shaving brush clings together when removed from water due to:
a) Surface tension
b) Viscosity
c) Elasticity
d) Friction
Answer: a
Buoyancy & Fluid Behavior
9. A steel ball dropped in a bucket full of mercury will:
a) Sink to the bottom
b) Float on the surface
c) Dissolve in mercury
d) None of the above
Answer: b
10. A steel ball dropped in a mercury container will:
a) Sink completely
b) Stay on the surface
c) Be partially immersed
d) Dissolve in mercury
Answer: c
11. On a clean glass plate, a water drop spreads out while a mercury drop remains spherical because:
a) Mercury is a metal
b) Mercury is denser than water
c) Cohesion of mercury is greater than its adhesion to glass
d) Cohesion of water is greater than its adhesion to glass
Answer: c
12. An ice block with a piece of lead embedded in it floats in water. When the ice melts, the water level:
a) Rises
b) Falls
c) Remains unchanged
d) Falls and then rises
Answer: b
13. A falling raindrop reaches terminal velocity. Which is true?
a) Terminal velocity varies for each droplet
b) All droplets fall at the same terminal velocity
c) Velocity keeps increasing with varied final speed
d) All droplets fall with the same final velocity
Answer: a
14. Two ice cubes pressed together form one block due to:
a) Hydrogen bonding
b) Van der Waals forces
c) Covalent bonding
d) Dipole interaction
Answer: a
Fluid Pressure & Properties
15. To calculate fluid pressure at the bottom of a vessel, which quantity is not required?
a) Height of liquid column
b) Bottom surface area
c) Liquid density
d) Acceleration due to gravity
Answer: b
16. Among the following, the most elastic material is:
a) Rubber
b) Wet clay
c) Steel
d) Plastic
Answer: c
17. Why does an oil drop spread over water?
a) Oil is lighter
b) Oil is more viscous
c) Oil does not mix with water
d) Oil has lower surface tension than water
Answer: d
18. Which vessel empties first when filled with water, mercury, and kerosene to equal height with identical taps?
a) Vessel A (water)
b) Vessel B (mercury)
c) Vessel C (kerosene)
d) All empty simultaneously
Answer: c