Question

Which of the following in not to be considered as a primary fuel?

• A. Wood
• B. Petroleum
• C. Coke
• D. Coal

Hint:

Primary = "As is" from nature. Secondary = "Processed" by humans.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Fuels are classified based on their occurrence. Primary fuels (Natural fuels) are used in the same form as they are found in nature. Secondary fuels (Derived fuels) are obtained from primary fuels through chemical or physical processes.
Step 2: Key Formula or Approach:
Identify which fuel is a manufactured byproduct rather than a naturally occurring resource.
Step 3: Detailed Explanation:

Wood, Coal, and Petroleum: These are all found naturally in the earth's crust or biosphere and are considered primary fuels.
Coke: This is a grey, hard, and porous fuel with high carbon content. It is produced by the destructive distillation of coal (heating coal in the absence of air). Because it is processed from coal, it is a secondary fuel.

Step 4: Final Answer:
Coke is not a primary fuel.