Heat Online Test 8th Science Lesson 9 Questions in English

1. Which among the following is not the important changes that we can see in our daily life due to heat energy as it supplied to substance?

2. Which among the following statement is correct

1) All the substances in our surrounding are made up of atoms and molecules. These atoms and molecules are always at static position. These static substances have an energy known as heat energy. This energy flows from cold substances to hot substances or from cold region to hot region of a substance.

2) When heat energy is supplied to any substance it increases the energy of the atoms and molecules in it and so they start to vibrate. These atoms and molecules which vibrate make other atoms and molecules to vibrate. Thus, heat energy is transferred from one part of the substance to other part. We can see this heat energy transfer in our daily life also. Heat energy brings about lot of changes.

3. When the water is heated, water molecules receive heat energy. This heat energy supplied increases which of the molecules?

4. In ice cubes the force of attraction between the water molecules is ___

5. Which among the following is incorrect regarding the Expansion effect of heat

1) Take a metal ball and a metal ring of suitable diameter. Pass the metal ball through the ring. You can observe that the metal ball can easily go through it. Now heat the metal ball and  then try to pass it through the ring. It will not pass through the ring. Keep the metal ball on the ring for some time. In few minutes, it will fall through the ring

2) When the ball is heated the atoms in the ball gain heat energy. They start vibrating and force each other apart. As a result, an expansion takes place. That’s why the ball did not go through the ring.

3) After some time, as the ball lost the heat energy to the surrounding it came back to its original size and it went through the ring. This shows that heat energy causes expansion and contraction in solids. This expansion takes place only in solid not in liquids and gases also. It is very rare in gases.

6. Which among the following statement is correct

1) When we heat the water, the force of attraction decreases further. Hence they move away from one another and become vapour. Since water vapour escape to the surrounding, water level decreases further. From this we understand that heat energy causes change in the state of the substances.

2) When heat energy is removed, changes take place in reverse direction. If heat energy is supplied to or taken out from a substance, it will undergo a change from one state of matter to another. There are six transformations may take place due to heat energy.

7. The solid to gas transformation is known as ____

8. The transformation of gas to sloid state is known as ____

9. The transformation of solid to liquid state is called as _____

10. The Transformation of gas to liquid state is known as ____

11. Which among the following is not transformation take place due to heat energy

12. Heat does not transfer by which among the following way?

13. Which among the following statement is correct

1) Leave the spoon inside the hot water for some time. The other end of the spoon become hot. It is because heat in the hot water is transferred from one end to another end of the spoon.

2) In solid substances such as silver spoon, atoms are loosely arranged. Hot water molecules which are vibrating transfer the heat energy to the atoms in the spoon and make them vibrate. Those atoms make other atoms to vibrate and thus heat is transferred to the centre of the spoon.

3) In conduction heat transfer takes place between two ends of the same solid or through two solid substances that are at different temperatures but in contact with one another. Thus, we can define conduction as the process of heat transfer in solids from the region of higher temperature to the region of lower temperature without the actual movement of atoms or molecules.

14. Which is the only matter on the Earth that can be found naturally in all three states – Solid, Liquid and Gas?

15. Which among the following is the bad conductor?

16. Which among the following is incorrect regarding conduction

17. Which among the following statement is incorrect

1) When water in the vessel is heated, water molecules at the to receive heat energy and move downward. Then the molecules at the bottom comes top and get heated. This kind of heat transfer is known as convection. This is how air in the atmosphere is also heated.

2) Thus, the form of heat transfer from places of high temperature to places of low temperature by the actual movement of molecules is called convection. Convection takes place in liquids and gases.

18. Which among the following statement is correct regarding convection

19. Which is defined as the way of heat transfer from one place to another in the form of electromagnetic waves?

20. Radiation does not pass through which among the medium?

21. Which among the following statement is correct

22. When a substance is heated to what temperature the radiation begins to become visible to the eye as a dull red glow, and it is sensed as warmth by the skin?

23. The amount of energy in food items is measured by the unit _____

24. The technique used to measure the amount of heat involved in a physical or a chemical process is known as ____

25. Which is a physical quantity which expresses whether an object is hot or cold?

26. Temperature is measured with the help of _____

27. Which among the following is not the scale to measure the temperature?

28. The unit of energy in SI system is ____

29. Which among the following is not the factor that determine the amount of heat energy gained or lost by a substance?

30. Which is defined as the amount of heat energy required by a substance to raise its temperature by 1°C or 1 K?

31. Which among the following is the correct formula of ; Heat capacity = ?

32. In the SI system, heat capacity is measures in ____

33. The temperature of a metal ball is 30°C. When an energy of 3000 J is supplied, its temperature raises by 40°C. Calculate its heat capacity?

34. Which is the amount of heat energy required to raise the temperature of 1 gram of water through 1°C?

35. The energy required to raise the temperature of an iron ball by 1 K is 500 JK^-1 . Calculate the amount of energy required to raise its temperature by 20 K?

36. Which is defined as the amount of heat energy required to raise the temperature of 1 kilogram of a substance by 1°C or 1 K?

37. Which among the following is the correct equation for Specific heat capacity =?

40. Which is the most commonly used scale to measure Temperature?

41. The specific heat capacity of a metal is 160 JKg^-1 K ^-1 . Calculate the amount of heat energy required to raise the temperature of 500 gram of the metal from 125°C to 325°C?

42. Which is a device used to measure the amount of heat gained or lost by a substance that consists of a vessel made up of metals like copper or aluminium which are good conductors of heat and electricity?

43. Which among the following statement is correct regarding calorimeter

1) The metallic vessel is kept in an insulating jacket to prevent heat loss to the environment. There are two holes in it. Through one hole a thermometer is inserted to measure the temperature of the contents.

2) A stirrer is inserted through another hole for stirring the content in the vessel. The vessel is filled with liquid which is heated by passing current through the heating element. Using this device, we can measure the heat capacity of the liquid in the container.

44. Which is a device which maintains the temperature of a place or an object constant?

45. The world’s first ice-calorimeter was used in the year 1782 by whom?

46. Which among the following statement is correct regarding thermostat?

1) Thermostats are used in any device or system that gets heated or cools down to a pre-set temperature. It turns an appliance or a circuit on or off when a particular temperature is reached.

2) Devices which use thermostat include building heater, central heater in a room, air conditioner, water heater, as well as kitchen equipment’s including oven and refrigerators. Thermostat functions as the sensor of a thermal system not as a controller

47. The Thermo Flask is also known as ____

48. Which among the following statement is correct regarding Working of Thermos flask?

1) A thermos flask has triple walls, which are evacuated. It is copper on the inside. The vacuum between the three walls prevents heat being transferred from the inside to the outside by conduction and convection.

2) With very little air between the walls, there is almost no transfer of heat from the inner wall to the outer wall or vice versa. Conduction can only occur at the points where the two walls meet, at the top of the bottle and through an insulated support at the bottom. The silvered walls reflect radiated heat back to the liquid in the bottle.

49. Which Scottish scientist invented Vacuum flask in 1892?