Combustion grade 8

Which of these isn't in the fire triangle?

• Fuel
• Heat
• Oxygen
• Carbon dioxide

In terms of ignition, identify which fuel sources would ignite from the easiest to the hardest.

• Dead grass, bricks, dead limbs
• Dead grass, live green branch, saw dust
• Saw dust, live green branch, dead limbs
• Dead grass, dead branch, live green branch

What will happen?

• paper cup will catch fire immediately

• paper cup will not catch fire

• water starts boiling and paper cup will catch fire in sometime

• paper cup will melt

Forest fire occur because of

• heat, moisture

• heat, dryness

• heat, friction and dryness

cleanest option of fuel for transportation

• Petrol

• Gasoline

• CNG

• Diesel

Most of the chemical energy released when gasoline burns in a car engine is not used to move the car, but is changed into

A. electricity

B. heat

C. magnetism

D. sound

• A

• B

• C

• D

Like fuel the sun also provides heat and light. The process taking place in the sun is called

a. Combustion

b. Nuclear process

c. Burning

d. All of these

• A

• B

• C

• D

A large log of wood will burn more slowly than the same log chopped into smaller pieces. Explain why.

• More heat given to the wood

• More surface area exposed to air

• Lower ignition temperature

Some chemical reactions absorb energy, while others release energy. Of the chemical reactions in burning coal and exploding fireworks, which will release energy?

•a Burning coal only

•b Exploding fireworks only

•c Both burning coal and exploding fireworks

•d Neither burning coal nor exploding fireworks

• a

• b

• c

• d

The best fuel

• Lower calorific value, higher ignition temperature, high CO2 emission

• Lower CO2 emission, lower calorific value, lower ignition temperature

• lower CO2 emisssion, higher calorific value, lower ignition temperature