Question

The primary cause of subsurface fires in underground mines is

• A. Over ash content in coal
• B. Spontaneous combustion of coal
• C. More carbon content of coal
• D. High levels of oxygen in the air

Hint:

Most underground coal mine fires originate due to \[ \boxed{\text{Spontaneous heating and combustion of coal}.} \]

Answer 1

The Correct Option is B

Step 1: Recall the main cause of underground mine fires. Subsurface fires generally occur when coal undergoes slow oxidation, generating heat that eventually leads to self-heating.

Step 2: Identify the primary cause. This phenomenon is known as \[ \boxed{\text{Spontaneous combustion of coal}.} \] Hence, \[ \boxed{(B)} \] is the correct answer.