Investigation Into the Resistivity of a Wire

Investigation Into the Resistivity of a Wire

Aim:

The aim of this investigation is to see how the length of Nichrome

wire affects its resistance

Pre-test Results:

Wire Type

Swags

Length of Wire

(cm)

Voltage

(v)

Current

(a)

Resistance

(Ω)

Constantan

26

10

20

40

13.5

27.5

56.4

0.4

37.5

687.5

1410

Copper

26

10

20

40

0.9

1.5

2.5

0.4

22.5

37.5

62.5

Nichrome

26

10

20

40

32.5

59.4

118.3

0.4

812.5

1485

2957.5

Pre-test Findings:

From my pre-test, I found out that using the nichrome wire would be

best to use because it gave the both more reliable results and were

also closer together. Constantan was not suitable for the

investigation because it gave very inaccurate results- the range was

very large. Copper was not suitable both because it had a very low

resistance, and also heated up very fast, so could burn someone.

Therefore I decided to use nichrome wire.

I also decided to use a wooden block to keep hold of the wire, because

it will keep the wire taut and also to prevent anyone getting burnt.

Another thing I decided was to use digital multimeters because they

give more accurate results- to 2dp- and can measure both the current

and voltage on the same instrument.

The ranges of lengths I will be using for my final investigation are:

0.2m, 0.4m, 0.6m, 0.8m and 1.0m.

Fair Testing:

The variable I am testing for this investigation is the length of the

wire I will be using.

v I will be keeping the following things the same:

Multimeters,