Explain how the use of CNG in automobiles has reduced pollution in our cities.
Answer:
Combustion of fuels like petroleum causes formation of un-burnt carbon particles along with carbon monoxide gas. These
harmful pollutants enter the air and cause respiratory diseases. Compressed Natural Gas (CNG) produces these harmful
products in very less quantity. It is a comparatively cleaner fuel. Therefore, the use of CNG has reduced pollution in our cities.
Abida and Ramesh were doing an experiment in which water was to be heated in a beaker. Abida kept the beaker near the
wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get
heated in a shorter time?
Give reasons.
(a) Water is not used to control fires involving electrical equipment.
(b) LPG is a better domestic fuel than wood.
(c) Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.
