• 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

# Investigate four factors that may affect the strength for electromagnets: the number of turns, the size of the current, the nature of the current (a.c. or d.c.) and the distance between the sensor and the magnet.

Extracts from this document...

Introduction

Strength of electromagnets

Design

Research question

Investigate four factors that may affect the strength for electromagnets: the number of turns, the size of the current, the nature of the current (a.c. or d.c.) and the distance between the sensor and the magnet. This experiment will be divided into 4 parts investigating each of the 4 factors.

For each part, the independent variable is one of the 4 conditions (the number of turns, the size of the current, the nature of the current (a.c. or d.c.) and the distance between the sensor and the magnet). The dependent variable is the strength received by the sensor. The controlled variables will be the room temperature and the other three factors.

Materials and methods

The materials I used are a magnet, a long copper wire, an ammeter, a sensor, power supply, a thermometer, a graphical calculator and a rheostat.

Part 1: Number of turns

1 Measure the room temperature and record as ‘t’.

2 Set the power supply as a.c., set the rheostat at position A and keep the sensor 5cm from the magnet.

Middle

50

58.5

63.6

54.3

60.2

61.5

Processed data

 Number of turns Average Strength of magnet/T 10 6.1 20 17.4 30 31.9 40 39.9 50 59.6

From the graph and the table, I can see that with the number of turns increased, the strength of the magnet increased as well.

Size of the current at t=23.4°C

 Strength of magnet/T Size of the current X1 X2 X3 X4 X5 Position A 15.4 14.5 15.6 15.9 17.1 Position B 26.5 27.8 26.9 27.3 28.2 Position C 34.9 33.9 35.5 37.6 39.5 Position D 44.5 49.3 46.7 47.5 46.1 Position E 62.4 67.6 64.3 64.7 65.2

A-E represents the change in position of the slide of rheostat and thus a change in the size of the current.

 Size of the current Average Strength of magnet/T Position A 15.7 Position B 27.3 Position C 36.3 Position D 46.8 Position E 64.8

Since no concrete number is used to measure the size of the current, it is very hard to draw a graph to show the relationship.

Conclusion

Conclusion and evaluation

The three factors: number of turns, the size of the current, and the distance between the sensor and the magnet will all affect the final result of the strength of the magnet yet the nature of the current (a.c. or d.c.) doesn't change the strength.

The experiment can be improved in these ways:

1: a different shape of magnet could be used compared to the bar-shape one, e.g. u-shaped. In this case the strength of the electromagnet is more powerful than a straight one for obvious reason that both poles can be used to attract and lift objects; but it’s actually much more than twice as powerful as a single pole. So I can expand my experiment to investigate the influence of the shape of the magnet.

2: I could also measure each length of the wire because as more coils were added the length of the wire had to get longer and the length of the wire could have been one of the variables. Then there would be two variables in the experiment failing to control the one investigated.

This student written piece of work is one of many that can be found in our AS and A Level Fields & Forces section.

## Found what you're looking for?

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

## Here's what a star student thought of this essay

4 star(s)

### Response to the question

The candidate has carried out an experiment to investigate how four factors affect the strength of the magnetic field of an electromagnet. They have successfully answered the question, but there is still a lot of room to develop their answer ...

### Response to the question

The candidate has carried out an experiment to investigate how four factors affect the strength of the magnetic field of an electromagnet. They have successfully answered the question, but there is still a lot of room to develop their answer further, for example comparing their results to formulae or explaining the physics behind the phenomenon. All their analysis needs to be written up in their conclusion, rather than a vague statement that three of the factors had 'an effect'. Additionally, they have used different settings for each experiment - for example they changed the number of turns on the magnet between experiments, which makes it harder to compare results. Also, they have failed to use the necessary equipment to be able to thoroughly analyse their results - an ammeter should be available within school for them to use, and is essential for analysing the results when they investigated the effect of changing the current. Despite this, they have still carried out the experiments well with consistent results, and used these to answer to original question.

### Level of analysis

The candidate has, where possible, analysed their results fairly well. They have drawn several graphs, calculated lines of best fit, and then described (albeit briefly) what these graphs show. However, they could have improved their analysis by drawing error bars on the graphs, showing calculations for identifying any anomalous results (every though there doesn't appear to be any, it's still good to check, and may be essential to gain marks), and describing the relationships between the variables and the strength of the magnetic field - for example describing it as 'inversely proportional'.

### Quality of writing

The candidate has fairly good spelling, punctuation, and grammar. However, they have not stuck to convention in places, for example using the past tense 'I used' in the method section, when 'I will use' is more conventional. Their descriptions of the method are very good, and could easily be followed by someone who had not seen them carry out the experiment. They have also included a diagram. However, the sections of the report need to be more clearly headed - with bold, underlined test for clarity and ease of reading.
Overall, the report is readable and does its purpose, but could be quickly and easily improved by changing the presentation slightly.

Reviewed by dragonkeeper13 09/09/2012

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 AS and A Level Fields & Forces essays

1. ## Determination of the acceleration due to gravity (g)

4 star(s)

the actual value x 100% Therefore: % different = 9.81 ms-2 - 9.375 ms-2 / 9.81 ms-2 x 100% = +/- 4.43% However the average time was calculated. This error in the measurement of time will be about 0.02s. it is more important to reduce the fractional error in the

2. ## How does the number of coils on an electromagnet affect its strength?

Another way that you can demagnetise a piece of metal is by heating it up, when you heat the metal up it gives the molecules energy and they scatter themselves. A longer way to demagnetise the piece of metal is to wait for the molecules to slowly scatter themselves, which will take quite a ling time.

1. ## Investigation to find out what affects the size of a shadow.

Distance from screen (cm) Size of shadow (cm) 10 6 20 7 30 11 40 22 Predicted Graph From looking at my results and my graph I can see that as the object gets closer and closer to the screen the shadow becomes closer to been the same size as the object itself.

2. ## The experiment involves the determination, of the effective mass of a spring (ms) and ...

the value of % unc in xT the following formula was used, % unc in xT = ?xT/S ? 100 T/S To find the value of % unc in T2 the following formula was used, % unc in T2 = 2 ?

1. ## To investigate the effect of current on the strength of an electromagnet field.

This will be easy to keep constant. 4. Number Of Coils To keep this constant, I will use the same number of turns coiled around the bar at each reading. To make sure the coils do not unwind, I will use insulation tape at each end of the bar, a

2. ## Measuring Young modulus of copper

Be wore safety goggle anytime when the experiment is processed. (V) Another G-clamp is used to fix the ruler which is measured the extension of the copper wire. 2. Errors (I) There was friction between pulley and the wire.

1. ## Viscosity Experiment. The aim of my investigation will be to analyse the relationship ...

After doing several online tests my reflex reactions averaged out to be 0.2 seconds. I was planning to use light gates at first, as this would have been much more accurate in measuring the time of the fall, but

2. ## How can I work out the Young's Modulus of copper wire?

properly aligned with the zero on the ruler, meaning that all the rest of the measurements are invalid.

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