Wednesday, 13 August 2014

HEAT QUESTIONS ICSE



HEAT QUESTIONS ICSE

NAME ---------------------------  CLASS-----------------------------  DATE -----------------

I.       FILL IN THE BLANKS:
1.Solids  --------------------------- on heating and ---------------------- on cooling
2. Among matter ----------------- expands the most and -------------------- the least.
3.Two bodies are said to be in the sate of thermal ----------------------- if there is no transfer of heat taking palce.
4. Liquids and gases are generally -------------------- conductors of heat.
 5.Ocean currents are caused by setting up of ------------------ in water
6.During night time cool breeze blows from ---------------------------- to ------------------
7.--------------------- and ----------------------------------- are good conductors of heat
8.Transfer of heat takesplace from body at ------------------- temperature to a body at ------------ temperature
9.Transfer of heat may take place by either ------------------------,--------------------------------
    or -------------------------.
10.Black surface are better than -------------------- of heat than polished surfaces.
11.Heat is a form of --------------------------
12. The fixed temperature at which matter is in a liquid state changes to its solid state is called------------------
13. Temperature is a measure of ----------------------- of a body
14. Increase in size of the object when heated is called ----------------------
15.Thermal expansion is maximum in --------------------
16. Temperature is the degree of ---------------------------- of a body,.
17. Heating of metals is through the mechanism of ---------------------
18. Land and sea breezes are caused by ----------------------------- currents
19. Example of a solid that sublime is ----------------
20. heat from the sun reaches us through the mode of ------------------

II. Differentiate the following
    1. Boiling and Evaporation







             

2.      Conduction and convection















3.      Conductors of heat and Insulators










III. Give reasons for the following



1.We wear woollen clothes in winter







2.Ice is wrapped in sawdust or a woollen blanket









3.      Why do houses with thatched roofs keep cool in summer?







        4.Why does an ice box have double walls?







5.      Cooking pots are provided with wooden or plastic handles? Why?






6.      We prefer white clothes in summer and dark co loured clothes in winter .Why?







    7.The top of asbestos is painted white.






    8. Gaps are left in between rails while laying railway tracks.






     9.Telephone wire are kept slightly loose when they are laid in summer.






10.  Bridges are mounted on Rollers.








11.  A thick glass Tumbler crack when hot wter is poured in it.









12.  The diameter of an Iron tyre is kept slighly smaller than the wooden wheel on which this tyre is to be mounted.








13.  We wear a number of garments in winter rather than one thick garment,


     

IV. Answer these questions

1. List three effects of heat on  an object





2.Name the three modes of transmission of heat energy







3. Name the four good conductors and four bad conductors of heat.