• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# The aim of this experiment is to investigate the relationship between the current, voltage and resistance through the use of a fixed resistor and a filament lamp.

Extracts from this document...

Introduction

Abdul Mufti                                               Centre Number: 13329                                 Candidate Number: 4138

10. F

Aim

The aim of this experiment is to investigate the relationship between the current, voltage and resistance through the use of a fixed resistor and a filament lamp.

Hypothesis

Based on knowledge of Ohm’s law it can be hypothesised that when an increasing voltage and current is passed through a filament lamp the resistance would increase in an irregular fashion, so that a graph similar to the one given below would be seen (figure 1). This curved graph would be expected due to temperature increases in the filament lamp.

It can also be hypothesised that when current is passed through a fixed resistor  a straight line graph would be obtained (figure 2) this  is explained in figure 3.    Circuit Diagrams   Equipment

Fixed resistor &

Filament Lamp         to impede and obstruct current flowing through circuit

Ammeter                 to measure current flowing through the circuit

Voltmeter–         to measure the voltage present in the circuit and to make sure the power supply is correctly calibrated.

Power Supply–         to act as the adjustable power source for the circuit

Wiresto connect the circuit components. Tangles were removed from the wires as not doing so could result in erroneous values being obtained in the experiment, as using several different wires or tangled wires during the experiment could lead to varied resistance and poor fair test (Figure 6). Middle

The equipment was then turned on. As the voltage on the PSU was increased it was confirmed on the voltmeter and the reading on the ammeter was noted. For the first circuit a total of 7 ammeter readings were taken and repeated. Each time the voltage was increased by 2 V.

The value for each voltage was recorded in the table. Once the highest voltage had been reached for the PSU the circuit was switched off and the fixed resistor was replaced with a filament lamp (figure 6). The voltage readings were then repeated as before and were inserted in another table. After this the equipment was cleared away. The tables were then plotted onto graphs.

Method in summary:

1. Apply safety precautions.
2. Gather equipment and connect it according to figure 4.
3. Recheck for safety and turn the circuit on.
4. Increase the Voltage by 2V every reading and note the current reading on the ammeter.
5. Once 12V is reached switch the PSU off.
6. Replace resistor with a Filament Lamp
7. Carry out steps 3-5 again.
8. Once readings for filament lamp and fixed resistor are tabulated clear up equipment.
9. Plot an I-V graph for the fixed resistor and Filament Lamp.

Variables

The controlled variables in this experiment are the resistors and equipment used.

Conclusion

To conduct a fair test it would have been practical to use averages for a series of current readings. This could be done by using two different sets of equipment, conducting the experiment on each set and averaging the values. This could help us reduce the margin of error in any anomalies found. It may have been interesting to investigate the same aim with a wider range and more sensitive set of equipment. Smaller increases of voltage on the PSU would have allowed us to plot the graphs with more accuracy. If possible it would have been interesting to use a diode. We may also have adjusted variables such as the thickness, length and type of wire used to investigate the effect these factors have on Ohm’s law and our graphs. we would also investigate how changing the circuit diagram would have affected our results.

However it would not have been possible because of time limitations

Bibliography

GCSE double Science Physics – CGP – ISBN: 1-84146-401-5

New Modular Science for GCSE, (Vol 1), - Heinemann (1996) – ISBN: 0-43557-196-6

AQA GCSE Science syllabus (2001).

A level Physics Letts Study Guide (reprinted 1996)

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics 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 AS and A Level Electrical & Thermal Physics essays

1. ## Single Phase Transformer (Experiment) Report.

Though small, these losses are of great economic and practical importance; all the electricity generated in a power station is transformed several times before it is put to use. If the losses at each transformer were 1%, it would result in 4 or 5% of all electricity production being wasted as heat in transformers.

2. ## Investigating the effect of 'length' on the resistance of a wire

The following calculations also prove what I have just said: The resistance at 10cm was 4.72?. If I then double the length, a resistance of 4.72 � 2 = 9.44? should be given. When I carried out the investigation 20cm gave me 9.09?, a small difference of 0.35?

1. ## Investigate the current - voltage relationship for a resistor and filament lamp. To determine ...

A gradient can be calculated to determine the resistance. A curved graph will show the alternative, that it is not an ohmic conductor. The p.d and current are not proportional. Ohms law can be presented mathematically by the equation V = IR which can be compared to the equation of

2. ## Investigation into the resistance of a filament lamp.

We know that Voltage is directly proportional to the current and Resistance is inverse proportional to current. I? V I ? 1 If we combine these two equations together we get I=V/R, if we re-arrange this formula we get ohm's law V=I.R.

1. ## Electrical Properties of a Filament Lamp - Does a Filament Lamp Obey Ohm's Law?

The filament lamp can become very hot so make sure that you do not burn yourself on it. Make sure none of the equiptment is faulty. Conclusion In conclusion the results graph proves that a filament bulb does not obey Ohm's law as the gradient changes in steepness and curves horizontally.

2. ## The aim of the experiment is to verify the maximum power theorem and investigate ...

Except we have to know how to use the beam balance correctly, we should know how to minimize depletion of the balance. When we do not use the beam balance, we have to move one of masses to the right-hand sides.

1. ## Investigation into the resistance of a filament lamp

Prediction I predict that by increasing the resistance we will also increase the temperature of the filament lamp. Also the filament is not an ohmic conductor. This is because we know that at high temperature the ions have more kinetic energy then they would have if the temperature was low,

2. ## Geothermal energy is not easily accessible with our current technology. Our main focus was ...

There are two main types of GHPs, closed loop systems and open loop systems. Closed loop systems run vertically or horizontally, depending on the space available. Open loop systems use wells or surface body water as the heat exchange fluid to circulate through the GHP system. • Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to 