Microwave energy has been used in this
country to cook and reheat food since early
experiments with RADAR in World War II.
Microwaves are present in the atmosphere all
the time, both naturally and from manmade
sources.
Manmade sources include radar, radio,
television, telecommunication links and mobile
phones.
Microwaving Principles
The microwaves cause the water molecules to
vibrate which causes FRICTION, i.e. HEAT.
This heat then cooks the food. Microwaves are
also attracted to fat and sugar particles, and
foods high in these will cook more quickly.
Microwaves can only penetrate to a depth of
1½-2 inches (4-5 cm) and as heat spreads
through the food by conduction, just as in a
traditional oven, the food cooks from the
outside inwards.
How Microwaves cook food
In a microwave oven, electricity is converted into
microwaves by the MAGNETRON.
REFLECTION
The microwaves bounce off the metal walls and
the metal door screen.
TRANSMISSION
Then they pass through the cooking containers to
be absorbed by the water molecules in the food,
all foods contain water to a more or lesser extent.
