Heat Transfer - Radiation Flashcards
1
Q
how does radiation occur
A
heat travels from one area to another, without the use of a medium (gas, liquid or solid). electro-magnetic waves (rays) make this possible.
2
Q
types of electro-magnetic waves
A
x-rays, light-rays, heat-rays, microwaves
3
Q
what are heat rays known as
A
infrared rays
4
Q
how is food cooked by radiant heat
A
food is cooked by radiant heat, either from above (grilling) or from below (braai)
a heater heats the surroundings by radiant heat
5
Q
effect of surfaces on radiation
A
- dark, dull surfaces absorb heat and promote cooking
- shiny or white surfaces reflect heat - slow down the cooking process
6
Q
methods of cooking where radiant heat is used to cook food
A
- grilling
- roasting
- toasting
