RFT 001/002/003

Question 1

What is an irreversible chemical reaction producing heat and light?

Answer 1

Combustion

Question 2

What are the three components of the fire triangle?

Answer 2

• Heat
• Fuel
• Oxygen

Question 3

What is heat measured in?

Answer 3

Joules per kilogram

Question 4

What factor is present in any combustion process and takes no part in the chemical reaction of combustion?

Answer 4

Passive agent (e.g. brick)

Question 5

What does the following describe? The substances making up the surface of the solid reacts with oxygen. The heat will be felt and seen as a glowing of the surface.

Answer 5

Surface oxidisation

Question 6

Define pyrolysis

Answer 6

The decomposition of a substance by heat

Question 7

Flash points are the lowest temperature at which…

Answer 7

…sufficient vapours are produced.

Question 8

A momentary flash occurs when…

Answer 8

…an ignition source is introduced.

Question 9

The burning of vapours (re flash points) does not continue once…

Answer 9

…the ignition source is removed.

Question 10

What is the lowest temperature at which a fuel will ignite and continue to burn without the need for an ignition source to be introduced?

Answer 10

Auto-ignition temperature (AIT)

Question 11

What is the meaning of SIT?

Answer 11

Spontaneous Ignition Temperature

Question 12

What are the three ways fires can spread?

Answer 12

• Convection
• Conduction
• Radiation

Question 13

In which three ways does water reduce the amount of fuel available to a fire?

Answer 13

• The rapid expansion of water to steam dilutes the flammable gases
• Reduces further production of flammable gases by the pyrolysis because of the reduction of heat
• The expansion of water to steam drives out some of the existing fire gases

Question 14

By starving a fire, which component of the triangle of fire will you be removing?

Answer 14

Fuel

Question 15

By smothering a fire, which component of the triangle will you be removing?

Answer 15

Oxygen

Question 16

What class of fire is carbonaceous solids?

Answer 16

Class A

Question 17

What is a Class C fire?

Answer 17

Gasses and liquefied gasses

Question 18

What extinguishing medium would be used on an electrical fire?

Answer 18

C02

Question 19

What are four passive agents?

Answer 19

• CO2
• Ceiling
• Water vapour
• Walls

Question 20

Convection is the mass movement of a hotter, less dense gas through…

Answer 20

…its cooler, denser surroundings.

Question 21

Conduction is the passage of heat through…

Answer 21

…a material.

Question 22

Radiation is the transfer of heat energy as…

Answer 22

…electromagnetic waves.

Question 23

The 3 correct descriptions of a flash point:

Answer 23

• the lowest temperature at which sufficient vapours are being produced
• a momentary flash to occur when an ignition source is introduced
• the burning of the vapours does not continue once the ignition source is removed

Question 24

Diffused Flame

Answer 24

• gases are not mixed before ignition
• unclean burn
• burn cooler
• flame colour orange/red
• less noisy
• lower velocity of the deflagration
• defined outline of the lower flame
• less efficient burning

Question 25

Premixed Flame

Answer 25

• gases are mixed before ignition
• burn cleaner
• burn hotter
• flame colour blue
• more noisy
• higher velocity of the deflagration
• more stable flame but harder to discern edges due to blurred flame
• more efficient burning

Question 26

Flashover Rule of Thumb

Answer 26

4-2-1
Corner 4 mins (x1)
On wall 8 mins (x2)
Centre of compartment 16 mins (x4)

Question 27

Signs of Backdraught

Answer 27

• fire with limited or no ventilation
• fire has been burning for some time
• fire gases being pushed out under pressure from gaps
• windows blackened with no visible sign of flame
• fire gases pulsing out from gaps

Question 28

Signs of Flashover

Answer 28

• a ventilated fire with an adequate oxygen supply
• flames visible in the fire gasses at ceiling level
• combustible material gassing-off due to pyrolysis
• high temperatures and an increasing rate of combustion
• neutral plane moving down
• a sudden increase in fire development
• pyrolysis at floor level in the compartment

Question 29

Specific heat capacity of water

Answer 29

4.18 kilo joules per kilogram

Question 30

How many kilojoules does it take to turn 1 kilogram of water into steam?

Answer 30

2260kj

Question 31

The 3 water application techniques:

Answer 31

• indirect
• direct
• gas cooling