The flammable limits of natural gas are defined as which of the following percentage ranges?

The flammable limits of natural gas are defined as the range within which natural gas can ignite and combust in the presence of air. The correct range is 5% to 15% by volume of natural gas in air. This means that if the concentration of natural gas in the air is below 5%, it is too lean to ignite, while concentrations above 15% are too rich, and combustion cannot occur. This specific range is critical for safety and operational practices in handling natural gas, as it indicates the conditions under which gas is capable of sustaining a flame. Understanding these limits helps prevent hazardous situations in both residential and industrial settings where natural gas is utilized.