Page 46 - Innovator's Science-8

4 Electricity: Magnetic and

Heating Effects

Intended Learning Outcomes
Electromagnets Uses of Electromagnets
Does a Current Carrying Wire Get Hot? How does a Battery Generate
Electricity?

Stepping Stones
1. What is the method of heat genera on in electrical appliances?

2. A cell or ba ery is considered dead when it can no longer hold or produce a
sufficient electric charge to power devices. How would you test if a cell or
ba ery is dead?

Electric current flowing through a wire creates a magnetic field around it,

which is called the magnetic effect of electricity . This effect was discovered
by Hans Christian Oersted and is used to make electromagnets that can
attract metals and are used in electric bells and motors. When electric
current passes through a wire, it also heats the wire due to resistance,
which is called the heating effect of electricity. This heating effect is used in
Hans Christian Oersted electric heaters, bulbs, and irons. So, electric current can produce both

magnetism and heat, which have many practical applications in daily life.

Activity-1 Aim: To show that an electric current flowing through a wire
produces a magne c field around it.
Experiential Learning
Materials Required: Collect a magne c compass, an electric
cell, a cell holder, two drawing pins, a safety pin, two nails, two
pieces of connec ng wires (one longer and one shorter), and
two small pieces of cardboard. a.
Steps:
Using two drawing pins, a safety pin, and a cardboard piece,
makes a switch.

• Place the cell in the cell holder.
• Fix two nails to a piece of cardboard as shown. b.
An electric circuit and
• Fix the middle por on of the longer wire stretched between the a magnetic compass
nails, such that it is slightly above the surface of the cardboard.
A ach one end of that wire to the cell holder and another end to the switch.

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Science-8