Page 22 - CHAPTER-1 (Electricity)

CHAPTER 1

ELECTRICITY

Keywords:

Resistor

• A component in an electric circuit which offers resistance to the flow of
electrons constituting electric current is known as resistor.
• These are used to make those electrical devices, where high resistance
is required.
• It reduces current in a circuit, e.g. alloys like nichrome, manganin and
constantan.

Rheostat Good conductor

• It is a variable resistor, which is used • A material which offers low
to control the flow of electric resistance to the flow of
current by manually increasing or electrons or electric current in
decreasing the resistance. an electric circuit is known as a
good conductor, e.g. silver,
copper, aluminium.
• Amongst these, silver is the best
conductor of electricity

Poor conductor Insulator

• A material which offers higher • A material which offers very
resistance than conductors to the high resistance to the flow of
flow of electrons or electric current electrons or electric current in
in an electric circuit is known as an electric circuit is known as
poor conductor, e.g. mercury, lead, an insulator, e.g. rubber, dry
stainless steel, alloys of iron and wood and plastic.
chromium. • Electric current does not flow
through them.

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