Question

The table below shows some fuels along with their calorific values and ignition temperatures.
$$\begin{array}{ccc}\text{Fuel}& \text{Calorific value (kJ/kg)}& \text{Ignition Temperature (}{}^{\text{o}}\text{C)}\\ \text{A}& \text{100}& \text{5}\\ \text{B}& \text{80}& \text{50}\\ \text{C}& \text{30}& \text{60}\\ \text{D}& \text{20}& \text{70}\end{array}$$
Which of these can be considered as an ideal fuel?

• A. B
• B. D
• C. C
• D. A

Answer 1

The correct option is A B

An ideal fuel should possess a high calorific value and a moderate ignition temperature. The ignition temperature must be higher than the room temperature.

$\bullet$ Fuel A has the highest calorific value. Its ignition temperature is much lower than the room temperature. Thus, it can not be considered as an ideal fuel.

$\bullet$ Fuel B has a high calorific value and moderate ignition temperature. Thus, it makes an ideal fuel.

$\bullet$ However, fuels C and D are not ideal fuels because they have low calorific values and high ignition temperature.