Question

The given table lists some substances as per their burning tendencies.
$$\begin{array}{cc}\text{Forms flame}& \text{Does not form a flame}\\ \text{CNG}& \text{Kerosene oil}\\ \text{Coal}& \text{LPG}\end{array}$$
Which of the following substances are incorrectly categorized ?

• A. LPG
• B. CNG
• C. Coal
• D. Kerosene oil

Answer 1

Answer: (A), (C)

The correct options are
A LPG
C Coal

The substances which vapourise during burning, give flames. For example, kerosene oil rises through the wick and is vapourised during burning and forms flames. Coal on the other hand is a solid substance, does not vapourise and does not produce flame.
LPG and CNG burn with a flame, this is because a flame is produced only when gaseous substances burn.