PACA FOUNDATION CLASSES. All questions are compulsory. PART-A.Use appropriate answer.Q1-In a solid, heat is transferred mainly by the process of: (a) Conduction (b)convection (b) Radiation (d)noneQ2-A good conductor of heat is:(a) wood (b)asbestos(c) air (d) mercuryQ3-In a liquid, heat is transferred mainly by:(a)conduction (b)convection(c) radiation (d)noneQ4-in convection, heat is transferred:(a) upwards (b)downwards(c) sideways (d)in all directions.Q5-In vacuum heat is transferred by:(a)conduction (b) convection(c) radiation (d)none.Q6-The fastest mode of transfer of heat:
(a)Radiation (b)convection(c) conduction (d)none.Q7-Heat loss from surface by radiation can be reduced by:(a) keeping it in dark.(b) blackening the surface.(c) polishing the surface.(d)keeping the surface in vacuum.Q8-In a thermos flask, the vacuum between its walls reduce the heat loss by:(a)conduction (b)convection(c)radiation (d)conduction, convection both. PART-BQ1. Name the different modes of the transfer of heat.Q2. What is good bad conductor of heat? Give two example of each.Q3.Arraange the following in order of their increasing heat conductivity:copper,air, water, mercury.Q4. Explain the process of conduction in solid.Q5.How does the process of conduction differ in metals and non metal. PART-CQ1-Name a metal which is a good conductor of heat.Q2-Name a substance which is a good insulator of heat.
Q3- Give the list of some common substance in order of their decreasingconductivity of heat.Q4-In winter, a piece of iron on being touched by hand appears colder than apiece of wood. Give reason.Q5- when a metallic wire gauze is brought over the frame of a burner,the flamedoes not pass through the wire mesh. Give reason.Q6-Explain briefly the process of heat transfer by convection.Q7-In a solid ,heat is not transferred by the process of convection.Give reason.Q8-It is possible to heat a liquid or gas? Explain in your words.Q9-Why is a room heater in a room installed near the floor of the room.Q10-By the process convection ,heat is always transferred vertically upwards.Givereason.Q11-the inside of a closed car parked In the son is much warmer.Explain.Q12-On opening the windows of a glass walled room, the insight temperaturefalls. Explain.Q13- A red hot iron wall a suspended from the celling of a room by a thin metallicwire.(a)Name the ways In which the ball losses heat.(b)Name the way by which it losses the heat least, given a reason for your answer.(c)Explain what role the air in the room plays in the loss of heat.Q14-Name the three process of the heat transfer and distinguish between them.Q15-What is green house effect ,name three green house gases.Q16-what is ecosystem.Q17-Draw carbon cycle.