Question

The calorific values of petrol and CNG are 45000 kJ/kg and
50,000 kJ/kg, respectively. If you have vehicle which can run on
petrol as well as CNG, which fuel will you prefer and why?


NCERT Class VIII
Science - Exemplar Problems

Chapter 6. Combustion and Flame

Answer 1

Since now a days it is our duty to protect the environment other than relying on the others to protect the generation from and the harmful effects of the global warming.

So we have to be cautious before using any kind of fossil fuel.

I think it is better to use CNG as it is much more eco friendly then petrol.

Answer 2

I will use the CNG fuel as there are two benefits of using this

the first benefit that the calorific value of CNG is higher than that of petrol so we will get more amount of energy from the given amount of fuel this will result in that we can travel more distance on the same amount of fuel if we prefer CNG

the second benefit is that the CNG is less polluting to environment in petrol and nowadays it is our duty to conserve nature so CNG is the best choice


thanks and regards