MADE BY - VARNIKA KAPOOR
POWERPOINT PRESENTATION FOR CLASS 7, SCIENCE, CHAPTER ELECTRIC CURRENT AND ITS EFFECTS.
This presentation is to help students as well as teachers.
3. ELECTRIC COMPONENTS
•The various elements that are
used to make an electric circuit
are called electric components.
•EXAMPLES- Cell, Battery,
Connecting wires, Bulb, Switch etc.
4. ELECTRIC SYMBOLS
•As it is difficult to show the electric
components in a circuit diagram.
•Thus, they are denoted by specific
symbols known as ELECTRIC
SYMBOLS
5. HEATING EFFECTS OF
ELECTRIC CURRENT
•Water heaters (geysers),
electric irons, room heaters,
etc. are some electric devices in
which heat is produced.
6. •Electricity produces heat, i.e.,
part of the electric energy is
converted into heat energy. This is
called heating effects of electric
current.
7. HEATING ELEMENTS
•All appliances which produce on passing
electricity are based on the principle
that heat is produced when electricity
is passed through a wire.This wire or
coil of wire is known as element/
heating element.
8. •The amount of produced heat in a wire
depends on the length, thickness and
the material of the wire.
•Good conductors are those which allow
electricity to pass through them.
•The amount of heat produced depends
on how good or poor a conductor the
material of wire is.
9. •More heat is produced if the material
of a wire is not a conductor.
•Hence, heating elements are made up
of materials which have low
conductivity or high resistance.
•Common materials used for heating
element are tungsten and nichrome.
10. •Nichrome is a material made up of
nickel, iron and chromium.
•The filament of an incandescent bulb is
made up of tungsten.
•For this reason, connecting wires,
which are made up of materials like
copper aren’t hot to touch.
11. HEATING ELEMENTS
•All appliances which produce on passing
electricity are based on the principle
that heat is produced when electricity
is passed through a wire.This wire or
coil of wire is known as element/
heating element.
