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HEAT MCQ ICSE CLASS 8

Updated: Mar 9





Tick (✔) The correct choice amongest the following

1. When a bimetallic strip (brass and invar) is heated : (a) it remains straight (b) it bends with brass on convex side (c) it bends with invar on convex side (d) it does not have a definite shape


2. A bimetallic strip is not used in : (a) thermostat(b) pendulum clock(c) fire alarm(d) electric iron


3. In solids thermal expansion is of : (a) three types(b) four types(c) five types(d) all of these


4. Linear expansion does not depend on the : (a) nature of material (b) original length of the body (c) the increase in temperature (d) original surface area of the body

Answers

Tick (✔) The correct choice amongest the following

1. (b) it bends with brass on convex side

2. (b) pendulum clock

3. (a) three types

4. (d) original surface area of the body

WORKSHEET

Select the correct alternative 

(a) In evaporation

  1. all molecules of liquid begin to escape out

  2.  only the molecules at the surface escape out

  3.  the temperature of liquid rises by absorbing heat from surroundings.

  4.  the molecules get attracted within the liquid.

(b) The rate of evaporation of a liquid increases when :

  1.  temperature of liquid falls

  2.  liquid is poured in a vessel of less surface area

  3.  air is blown above the surface of liquid

  4.  humidity increases.

(c) During boiling or vaporization

  1.  all molecules take part

  2.  temperature rises

  3.  no heat is absorbed

  4.  the average kinetic energy of molecules increases.

(d) The boiling point of a liquid is increased by

  1.  increasing the volume of liquid

  2.  increasing the pressure, on liquid

  3.  adding ice to the liquid

  4.  decreasing pressure on liquid.

(e) Two rods A and B of the same metal, but of length 1 m and 2 m respectively, are heated from 0°C to 100°C. Then

  1.  both the rods A and B elongate the same

  2.  the rod A elongates more than the rod B

  3.  the rod B elongates more than the rod A

  4.  the rod A elongates, but the rod B contracts.

(f) Two rods A and B of the same metal, same length, but one solid and the other hollow, are heated to the same rise in temperature.Then

  1.  the solid rod A expands more than the hollow rod B

  2.  the hollow rod B expands more than the solid rod A

  3.  the hollow rod B contracts, but the solid rod A expands

  4.  both the rods A and B expand the same.

(g) A given volume of alcohol and the same volume of water are heated from the room temperature to the same temperature then.

  1.  alcohol contracts, but water expands

  2.  water contracts, but alcohol expands

  3.  water expands more than alcohol

  4.  alcohol expands more than water.

(h) The increase in length of a metal rod depends on

  1.  the initial length of the rod only

  2.  the rise in temperature only

  3.  the material of rod only

  4.  all the above three factors.

(i) The correct statement is