G3 Core Concepts and Principles 2

Question 1

What is the primary component of natural gas used in Ontario residential heating?

Accepted Answer

Methane

Answer

Natural gas is primarily methane (CH4), making up 85-95% of the mixture.

Question 2

What does 'specific gravity' mean in relation to natural gas?

Accepted Answer

The ratio of gas density to air density

Answer

Specific gravity compares gas density to air density, with air at 1.0.

Question 3

What is the approximate heating value of natural gas per cubic foot?

Accepted Answer

1,000 BTU/ft³

Answer

Natural gas has approximately 1,000 BTU per cubic foot.

Question 4

What are the three elements of the fire triangle?

Accepted Answer

Fuel, oxygen, and heat (ignition source)

Answer

The fire triangle requires fuel, oxygen, and heat. Removing any one prevents combustion.

Question 5

What is the flammable range of natural gas in air?

Accepted Answer

5% to 15%

Answer

Natural gas has a flammable range of approximately 5% to 15%. Outside this range it will not ignite.

G3 - Gas Technician Level 3 Certification Practice Test