Investigating the Effect the Thickness of a Wire has On Its Resistance

Investigating the Effect the Thickness of a Wire has On Its Resistance

Equipment:

Nickel Wire cut into 10 pieces of 30cm length (Ruler, Pliers)

Two crocodile clips

Five Pieces of Wire

Power Source

Variable Resistor

Ammeter

Volt Meter

Method:

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F The Circuit was set up as in the circuit diagram overleaf with a

power source of 5 Volts, an ammeter, crocodile clips (holding wires),

and a variable resistor in series and a Voltmeter in parallel with the

wires.

F Nickel chrome wire was then measured to discover the cross section

width with a micrometer screw gauge and this was recorded and the

cross sectional areas was calculated using πr² multiplied each time by

the number of wires used, each bit of wire was cut into lengths of 30

cm

F The crocodile clips held one piece of nickel chrome wire of

thickness 34 mm and length 30 cm at the same point on the ends of the

wire.

F The power source, ammeter and voltmeter were then switched on.

F The voltage and current for the wire were then recorded, and

recorded again when the variable resistor's slider was moved to the

middle and again when the slider was moved to the end.

F The Power was turned off while another was added to avoid

overheating.

F Another wire, or exact same properties (Nickel Chrome, thickness 34

mm and length 30cm) was placed on top of the previous wire, in the

same position, both straight and flat.

F The Power was turned on again and the same procedure was repeated,

recording current and voltage at three points on the variable

resistor.

F This was repeated 10 times in all, each time, an extra wire of exact

same properties (Nickel Chrome, thickness 34 mm and length 30cm) was

placed on top of the previous wire in the same position, all straight

and flat and the current and voltage was recorded at three points on