• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6
7. 7
7
8. 8
8

# What can affect the resistance of nichrome wire?

Extracts from this document...

Introduction

Investigating Resistance – What Can Affect the Resistance of Nichrome wire?

Background Knowledge: Metals conduct electricity because they have free electrons. This means that they are able to move around the positive ions like a sea. The positive ions are unable to move. This “sea” of electrons is moved by the force of the voltage pushing it around the circuit. The electrons move from negative to positive, the opposing current moves from positive to negative.

The formula for resistance is described as –

Resistance = Voltage / Current

Or

R = V / I                                                   (R=resistance

V=voltage

I=current)

I will use this formula to work out the resistance of my wire each time. I will now need to select a variable.

The resistance of a metal is low, but not zero. A voltage difference is still required to generate current in the metal and the metal heats up when the current is flowing. This increase in temperature is one four possible variables that I have come up with…

Possible Variables:                WIDTH

LENGTH

TEMPERATURE

TYPE OF WIRE

## Independent:                THE WIDTH OF THE NICHROME WIRE

(input variable)

Dependent (outcome variable): The resistance will be found by taking an Ammeter and then take one from a Voltmeter. The resistance is found by dividing the voltage by the current

R = V / I

Controlled: I will keep everything the same except the width of the wire.

Middle

With my results, I will now form a series of tables which will lead to the drawing of numerous graphs of analysis. I will plot one of the tables in a graph of diameter of wire against average resistance. If the graph is not a straight line, I will try 1 / diameter of wire against average resistance. If this graph fails, my last attempt will be 1 / diameter of wire squared against average resistance.

Darren Cave 12B                Page                 5/2/2007

My first set of results are shown in the table below –

WIRE WIDTH (mm)

CURRENT

(amps)

VOLTAGE

(volts)

### RESISTANCE

(ohms)

0.32

0.73

2

2.73

0.37

1.14

2

1.75

0.45

1.87

2

1.07

0.56

2.67

2

0.75

0.71

5.00

2

0.40

The second set of results that I recorded are shown in the table below –

WIRE WIDTH (mm)

CURRENT

(amps)

VOLTAGE

(volts)

### RESISTANCE

(ohms)

0.32

0.73

2

2.73

0.37

1.12

2

1.79

0.45

1.64

2

1.22

0.56

2.74

2

0.73

0.71

5.00

2

0.40

The not essential third set of results are shown in this table (dashes show where I felt a repetition was not required) –

WIRE WIDTH (mm)

CURRENT

(amps)

VOLTAGE

(volts)

### RESISTANCE

(ohms)

0.32

-

-

-

0.37

-

-

-

0.45

1.74

2

1.15

0.56

-

-

-

0.71

-

-

-

Conclusion

My three graphs were         diameter of wire against average resistance

1 / diameter of wire against average resistance

1 / diameter of wire squared against average resistance

In the first two graphs I was unable to find a straight line or a connection between the two factors, they made curves. The third graph gave a straight line through the origin and found the connection for me. The resistance is directly proportional to 1 / the diameter squared.

As I found a connection between the variable and the resistance, I consider this experiment to be a success so there is little I would change if I had another chance. The one problem I had was when I was trying to keep the wire 10cm in length. It was hard to get the wire completely straight so it could be measured accurately. Fortunately, this problem was not reflected in my results so I feel that the wires were measured accurately.

The aim of my coursework was to determine a formula linking the diameter of nichrome wire and the resistance of nichrome wire. So to conclude, as I successfully completed my objective, I consider the experiment to be a complete success.

Darren Cave 12B                Page                 5/2/2007

This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related GCSE Electricity and Magnetism essays

1. ## An experiment to find the resistivity of nichrome

length of wire "GCSE Physics Resistance of a Wire" Extended Title: "Investigation of factors that affect resistance of a wire" Before starting my coursework I have decided to chose a factor that will affect the resistance of a wire. I shall do this by going through all of the factors

2. ## How does length and width affect resistance

This will partly avoid systematic error. 2. Use the same voltmeter, ammeter and power pack. 3. When experimenting with diameter of wires de sure to use the same type of wire for e.g.: copper and constant are two different types of wires so be sure to use Constance.

1. ## Find out how the length and width affect the resistance of a graphite track.

To make sure my readings are as precise as possible I will measure the length of the carbon track with a ruler with millimeter values on it. The resistance in ohms will also be measured to 2 d.p. by the ohmmeter.

2. ## Investigation on the Resistance of Nichrome wire

Increase the length by 100mm until I reach 1000mm. This will give me a wide range of results to draw a graph. 6) Repeat the whole experiment two more times making sure I use the same pieces of apparatus so nothing changes to make my experiment fair.

1. ## Resistance of Nichrome Wire

(Higher current means higher temperature). This affects and changes a variable which could affect the results. * Make sure the circuit is setup in the same way: Once I have drawn a plan of the circuit I will use, I will not change it or add extra pieces of equipment: I.E.

2. ## Investigate how resistance can affect the amount of current flow.

Material is very important, some are better. The best conductor is silver but the least reactive is gold. Reactivity is more important in long time so gold is more used in important systems. Copper is the material which is widely used because it is both a good conductor and does not react easily.

1. ## Study on how different parameters can affect the resistance of a wire.

The diameter of the wire can also affect the resistance of the wire because if a wire has a large crossectional area i.e. a thick wire there is more room for the electrons to pass through, thus there will be less resistance per electron.

2. ## To find the affect of resistance of a piece of Nichrome wire.

Doubling the length will double the resistance. I have plotted this on a graph, we get a straight line as shown: [image002.gif] Ohm's Law It is also relevant to know of Ohm's Law, which states that the current through a metallic conductor (e.g. wire) at a constant temperature is proportional to the potential difference (voltage).

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to