SLIP TEST-VIIIC-SCIENCE & TECHNOLOGY

COMBUSTION AND FLAME

1.Substances which catch fire are called:-a) Burners  b) Combustible  c) Acid  d) Base
2.The lowest temperature at which substance catches fire is:-
a) Boiling temperature b) Melting temperature c) Body temperature  d) Ignition temperature
3.Charcoal burns with a:-a) Flame  b) Glow c) Both a and b d) None of these.
4.Burning of coal in a closed room will produce:-
a)Oxygen   b)Nitrogen    c)Carbon monoxide   d)Carbon dioxide
5.An ideal fuel has:-
a) Low calorific value    b) High calorific value  c) Major pollutant   d) Cannot be transported.
6.Can the process of rusting be called combustion?
7.What is the difference between the burning of a candle and the burning of a fuel like coal?
8.A matchstick does not catch fire on its own at room temperature. Why?
9.Can you list out the names of some inflammable substances?
10.What is the unit in which the calorific value of a fuel is expressed?
11.There is global warning on global warming. Which gas concentration leads to this problem?
12.When a fire brigade arrives at the accident spot what does he do?
13.Carbon-di-oxide is the best fire extinguisher. Give reason.
14.In what form is LPG stored in cylinder?
15.Water is not used to control fires involving electrical equipment. Give reason.
16.Why LPG a better domestic fuel than wood?
17.Ravi and Sita were doing an experiment in which water was to be heated in a beaker .Ravi kept the beaker near the wick in the yellow part of the candle. Sita kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time?
18.What are the criteria you would consider when trying to categorise something as a good fuel?
19.It is difficult to burn a heap of green leaves but dry leaves catch easily. Why?