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TEXT C. THE EFFECTS OF AN ELECTRIC CURRENT
Before you read the text, invite your ideas to consider what effects of
an electric current exist
Read the following text and give a title to each paragraph
1.
2.
3.
4.
5.
THE EFFECTS OF AN ELECTRIC CURRENT
1. The effects of an electric current are thermal, luminous, chemical and
magnetic.
2. When a current flows through a conductor it
may heat the conductor
.
This heat is sometimes
undesirable
and has to be reduced. For this reason,
many electric motors and generators contain a fan.
However,
domestic
appliances, such as electric cookers, and many
industrial processes
depend on
the heating effect of an electric current.
3. The passage of a current may produce light. This can happen in a
number of ways. The heat generated by the current may be so great that the
conductor becomes
incandescent.
For example, the filament of a light bulb
emits intense white light when heated by a current. Light is also produced
when
a current ionizes a gas
. The colour of the light will vary according to the gas
used. Mercury vapour lamps give a
greenish-blue
light.
4. An electric current can separate a chemical compound into its
components. This is called
electrolysis.
Chlorine is generated by the
electrolysis of salt water. Electrolysis can also be used to break down water into
