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ammeter again registered a current but in the opposite direction.
Faraday’s experiments were only the first steps, but he had
shown quite clearly that magnets could be used to produce an
electric current. The next step was to show that a momentary
movement should induce a continuous current. This is the
principle on which all electric generators (and motors) are based.

LESSON 3

STUDY SECTION

Copper is a good conductor of electricity. If a copper wire is
connected to a battery, an electric flows in the wire. However a
current does not flow if you connect a piece of plastic to the
battery. Because plastic is an insulating material, it resists the flow
of electricity. Bad conductors of electricity have a high resistance.

Look at this diagram. It shows an electric circuit:
battery

wire

lamp gap

Place a piece of copper wire across the gap. The lamp
lights. Current flows around the circuit. After removing the
copper, place a piece of nichrome across the gap. The lamp is
dimmer. Nichrome has a high resistance and the current does not
flow easily. This fire uses electricity for heating. The heating
element is made of nichrome, which is a bad conductor of
electricity. It has a high resistance and current cannot flow easily.
Therefore, the current passing through the element generates heat.

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