1 In which of the following materials does heat transfer primarily occur by convection? A A solid iron rod B A vacuum C A liquid or gas D A wooden block
2 Why are gaps left between railway tracks? A To allow for expansion in summer B To save construction material C To make trains move faster D To reduce friction
3 Thermal expansion refers to the increase in which property of a substance when heated? A Mass B Density C Volume D Color
4 Which of the following is the correct definition of heat? A The measure of the average kinetic energy of particles B The total kinetic energy of all particles in a body C The transfer of energy due to a temperature difference D The amount of matter in a body
5 Why is water used as a coolant in automobile engines? A It has a low boiling point B It is a good conductor of heat C It has a high specific heat capacity D It expands on heating
6 Gaps are left between railway tracks because: A To save material B To allow for expansion in summer C To reduce friction D To make the track stronger
8 What is the boiling point of pure water at normal atmospheric pressure? A 100°C B 0°C C 373 K D Both A and C
10 Why do automobile engines have gaps between metal parts? A To allow for thermal expansion when the engine gets hot B To reduce the weight of the engine C To allow air to escape from the engine D To make the engine look better
11 The main difference between conduction and convection is that convection involves A no medium B movement of the heated material itself C transfer by direct contact only D transfer by electromagnetic waves
12 What is the melting point of pure ice at normal atmospheric pressure? A 0°C B 100°C C 273 K D Both A and C
13 A bimetallic strip bends on heating because A both metals expand equally B metals expand by different amounts C one metal contracts D the strip becomes heavier
14 Which of the following statements correctly describes the difference between heat and temperature? A Heat is a measure of the average kinetic energy of particles, while temperature is the total energy transferred. B Heat is the total thermal energy of a body, while temperature is the average kinetic energy of its particles. C Heat and temperature are the same physical quantity expressed in different units. D Heat is measured in degrees Celsius, while temperature is measured in joules.
15 Gaps are left between railway tracks primarily to: A Allow for expansion in summer B Reduce friction C Save materials D Make repair easier
17 A bimetallic strip bends when heated because: A Both metals expand equally B The two metals expand unequally C One metal contracts D It is magnetic
18 During melting, the temperature of a pure substance: A Increases continuously B Decreases continuously C Remains constant D Fluctuates randomly
19 In which direction does heat naturally flow? A From cold body to hot body B From hot body to cold body C From both hot and cold bodies equally D Heat does not flow
20 The temperature of a body is a measure of: A Total heat energy in the body B Average kinetic energy of its particles C Total potential energy of its particles D Its mass
22 Which of the following statements correctly distinguishes between heat and temperature? A Heat is a measure of the average kinetic energy of particles, while temperature is the total energy transferred. B Heat is the total kinetic energy of particles, while temperature is the average kinetic energy of particles. C Heat is a form of energy transferred due to temperature difference, while temperature is a measure of the average kinetic energy of particles. D Heat and temperature are the same physical quantity.
23 Which of the following statements about heat and temperature is correct? A Heat is a form of energy, temperature is a measure of hotness B Heat and temperature are the same C Temperature is a form of energy, heat is a measure of hotness D Heat is measured in degrees Celsius
25 Which of the following is a daily life example of thermal expansion? A A metal lid stuck on a glass jar loosened by running hot water B Ice melting in a glass C Water boiling in a kettle D Clothes drying in the sun