Heat Transfer

1. Thermal conductivity increases as you increase in cross-section area of a material?

Question 1 of 44

2. Which of the following is not among the factors affecting thermal conductivity?

Question 2 of 44

3. SI UNIT of heat is?

Question 3 of 44

4. Metals are good conductors of heat?

Question 4 of 44

5. A body emitting thermal radiation can also emit visible light when it is hot enough?

Question 5 of 44

6. Explain how a spoon dipped in hot water shortly gets hot at the free end?

Question 6 of 44

7. What is the name given when you mix hot and cold parts of the fluid using external stirring such as fan or pump?

Question 7 of 44

8. When you heat water in a sufuria what happens?

Question 8 of 44

9. Why are exhaust pipes in a ship covered with thick asbestos material?

Question 9 of 44

10. Between a white car and a black car which one will absorb more heat than the other when you place both cars in an open field at 12 noon in Mombasa?

Question 10 of 44

11. Black (dull) materials are better emitters of heat than white (shiny/polished) material?

Question 11 of 44

12. Why are electrolytes better conductors of heat than pure liquid?

Question 12 of 44

13. Convection is:

Question 13 of 44

14. Explain why steam pipes in industry are lagged with poor conductors of heat

Question 14 of 44

15. Conduction can take place in solids?

Question 15 of 44

16. DEFINE heat

Question 16 of 44

17. Radiation is the flow of heat from one place to another by means of electromagnetic waves?

Question 17 of 44

18. Rate of heat flow is directly proportional to the temperature difference. True or False?

Question 18 of 44

19. Explain why a copper rod gets hot earlier than an iron rod of the same shape and size and all put in the same heat source

Question 19 of 44

20. Gases are the worst conductors of heat because of large inter-molecular distance?

Question 20 of 44

21. Thermal equilibrium is when 2 bodies at the same temperature are in contact and there is no heat flow?

Question 21 of 44

22. What makes Radiation mode of heat transfer different from conduction and convection?

Question 22 of 44

23. Explain reason why warm water in a heated sufuria rises and replaced by cold water from the top?

Question 23 of 44

24. Which of the following is not a property of the radiant heat from the sun?

Question 24 of 44

25. Which of the following is the main difference between metals and non-metals?

Question 25 of 44

26. Conduction can take place in liquid and gases?

Question 26 of 44

27. Non-metals are poor conductors of heat?

Question 27 of 44

28. Rate of heat flow is directly proportional to cross-section area of a conductor. True or False?

Question 28 of 44

29. Is the temperature difference between the ends of the conductor a factor affecting its thermal conductivity?

Question 29 of 44

30. Rate of heat flow increases or decreases according to the nature of material?

Question 30 of 44

31. Which of one the following explains why Liquids are poor conductor of heat?

Question 31 of 44

32. Convection currents move faster in

Question 32 of 44

33. Is water a poor conductor of heat?

Question 33 of 44

34. Thermal conductivity increases as you decrease the length of a metal (material)?

Question 34 of 44

35. Rate of heat flow is inversely proportional to the length of a conductor. True or False?

Question 35 of 44

36. Black materials are better absorbers of heat than white material?

Question 36 of 44

37. How is heat transferred from the sun to the earth?

Question 37 of 44

38. Define Lagging

Question 38 of 44

39. Thermal conductivity depends on the nature of the material (metal) such as iron and copper?

Question 39 of 44

40. Name the two mechanisms of thermal conduction in metals

Question 40 of 44

41. Which of the following is NOT a mode of heat transfer?

Question 41 of 44

42. Different metals have different thermal conductivities

Question 42 of 44

43. Which of the following is not an application of convection in fluids

Question 43 of 44

44. Which of the following describes an application of thermal radiation?

Question 44 of 44