Resistance of a Wire Investigation
Aim:
To investigate the effects of resistance on a nichrome wire
Planning
My planning will begin with providing a background understanding on
the theory of resistance and how it participates in the overall
process of the electric current. Reistance is simply a force which
challenges the flow current. Resistance is like car racers racing
round a track, the more friction there is due to the conditions, and
the material of the tyres, the more slower the car will move,
similarly an electric current with a more resistant material, causes
more resistance thus makes the current move slower. The electrons are
like the cars, as they move round the circuit they collide with
positive ions and the current slows down creating resistance.
The unit of resistance in an electric current is the ohm, (or known as
the greek letter omega). The formula for resistance is as follows:
Resistance ( R ) = Voltage(V) / Current (I)
The investigation is split into 3 experiments, the experiment will be
on the length of a nichrome wire, the second experiment will be on the
length of a copper wire, and finally the third experiment shall be on
the cross sectional area of the nicrome wire.
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Equipment
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· Nicrome wire, in 3 different cross sectional areas
· Copper wire
· Battery
· Crocodile clips
· Ammeter
· Voltmeter
· Pliers
· 1 metre ruler
· Micrometer
These are the constant variables that I will test in the first
experiment
· The wire will be nichrome and will stay as nichrome
· The voltage
· Cross sectional area
· Room temperature
These values must be kept at a constant, to keep the experiement as a
fair test.
The length of the wire will range from 10cm to 100 cm each time
increasing by 10 cm.
I will take note of the current and the voltage because this will be