Different methods of extinguishing a fire involve the following :
I. Removing the combustible substance.
II. Cooling the substance to a temperature below its ignition temperature.
III. Cutting off the supply of air.
Which of the following statements is correct?
A Method I is suitable in case of a building on fire.
B Method II involves water which works when wood or paper are on fire.
C Method III involves carbon dioxide gas which is lighter than oxygen and forms a blanket around the air.
D All of these
whats wrong with B
Ans 9:
Class : Class 9
not all of these we if u see option a it says to remove the entire combustible material nut how can you remove an entire building if it is on fire?
Ans 11:
Class : Class 8
It is option 'b', since you cannot remove the building as mentioned in option 'a'. Water does reduce the temperature of both wood and paper below their ignition temperature to combust fire. Option 'c' is partially correct but also wrong since co2 does form a blanket around the flame, cutting out o2 supply, but it does this because it is heavier then o2, not light.
Ans 13:
Class : Class 8
It is B because U cannot remove the building and in option C, CO2 is heavier not lighter thann Oxygen
Ans 14:
Class : Class 8
answer is D formation of a blanket around the oxygen gascuts off the supply of oxygen !!also cooling it down