Regelation

Q.

When ice melts, its volume______.

1. Increases

2. Decreases

3. Remains same

4. Cannot be determined

Q. The phenomenon in which the ice converts to liquid due to applied pressure and then re-converts to ice once the pressure is removed is called_________.

1. condensation
2. regeneration
3. regelation
4. evaporation

Q.

The boiling point of a liquid is decreased by

1. increasing the volume of liquid

2. increasing the pressure on liquid

3. adding ice to the liquid

4. decreasing pressure on liquid.

Q.

12. Aquatic animals are able to survive in the water bodies like rivers and oceans during winter when the atmospheric pressure is -10⁰C. This is because

1. density of ice is less than water

2. density of water is minimum at 4⁰C

3. ice is a poor conductor of heat

4. Both A and B

Q. During severe winters when lakes are frozen, fishes still survive. Why?

1. The ice acts as an insulator and thus prevents low thermal currents to reach the bottom
2. The fishes can withstand very low temperatures
3. The fishes remain in the state of hibernation
4. The bottom of the lake is not frozen

Q.

Density of solids cannot be changed by applying pressure.

1. True
2. False

Q. A steel wire with heavy mass suspended from it​ can cut through both the ice and wax blocks, ​ but only the wax block is obtained in two pieces because ____.​

1. molten wax is denser than solid wax​
2. molten wax is denser than water
3. ice is denser than water
4. water is denser than ice

Q. Explain regelation.

Q.

Calculate the time required to melt a certain mass of ice at -10⁰C completely, if it takes 20 minutes for the same mass of water at 0⁰C to become water at 85⁰C, using the same heater.

1. 30 minutes

2. 20 minutes

3. 10 minutes

4. 40 minutes

5. 50 minutes

Q. Skating of ice is possible because of the phenomenon of

1. friction
2. sublimation
3. regelation
4. latent heat of fusion

Q. One end of a cylindrical rod is kept in stem chamber and the other end in meting $ICE$. Now $0.5gm$ of ice melts in $1sec$. If the rod is replaced by another rod of same length , half the diameter and double the conductivity of the first rod, then rate of melting of ice will be

1. $0.25gm/sec$
2. $0.5gm/sec$
3. $1gm/sec$
4. $2gm/sec$

Q. Snow balls form due to

1. melting of ice
2. freezing of atmospheric moisture
3. regelation
4. sublimation

Q. Ice formed over lakes has

1. Very high thermal conductivity and helps in further ice formation
2. Very low conductivity and retards further formation of ice
3. It permits quick convection and retards further formation of ice
4. It is very good rediator

Q. What is regelation?

Q. Two liquid drops have their diameters as $1mm$ and $2mm$. The ratio of excess pressure in them is

1. $1:2$
2. $2:1$
3. $4:1$
4. $1:4$