A newly planted sapling usually grows and matures into a tree in more than:
A. 50 years

B. 25 years

C. 45 years

D. 15 years

Arrange the following fuels in order of increasing calorific values (keeping the fuels with lowest calorific value first):

LPG, Coal, Alcohol, Dung cakes, Diesel

Arrange the following fuels in the order of decreasing calorific values (keeping the fuels with highest calorific value first):

Biogas, Kerosene, Wood, Petrol, Hydrogen gas, Methane

Explain why, natural gas is considered to be a good fuel.

The calorific values of three fuels A, B and C are 33 KJ/g, 150 KJ/g, respectively. A is solid, B is liquid and C is a gas at room temperature. On combustion, both A and B produces carbon dioxide while C explodes forming steam. B and C leave no residue after combustion while A leaves behind some solid residue. Which one of the three fuels is the most ideal? Give two reasons to support your answer.

Name the product of petroleum that is used to drive heavy vehicles.

Which one of the following is not renewable energy technology?

One of the following is not a characteristic of a good fuel. This is:

Which of the following is more environment friendly ?

Why is LPG considered a better fuel than coal for cooking purposes?

Out of these renewable sources of energy is ________
a) coal
b) rock oil
c) petrol
d) wind