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

How a filament light bulb effects current and voltage.

Extracts from this document...

Introduction

Phillip Moore

GCSE Science

How a filament light bulb effects

current and voltage

Prediction:

My prediction is that the first experiment I will do which is the fixed resistor will follow ohms laws correctly. In the second experiment I will change the fixed resistor with a filament light bulb, this experiment will not follow the rules of ohms law.

Back ground information:

States that the steady electrical current in a metallic circuit is directly proportional to the constant total electromotive force in the circuit. If a current I flows between two points in a conductor across which the potential difference (voltage) is E, then E/I is a constant (which is know as the resistance, r, between the two points). Hence E/I=r. Equations relating E, I and R are often quoted as ohm’s law, but the term ‘resistance’ did not enter into the law as originally stated. From the Hutchinson Encyclopedia.

Equipment list:

The equipment I used were these:        

          •Power pack

          •Wires

          •Voltmeter

          •Ammeter

          •Variable resistor (rheostat)

          •Fixed resistor

          •Filament light bulb

Diagrams:  

This is the first diagram of the first test,

This has the fixed resistor in it, the

...read more.

Middle

5Turn the power pack off move the variable resistor

6Repeat this 7 times to make the experiment fair

7Now swap the fixed resistor with a filament light bulb

8Take the readings as before and turning it on and off like before and repeat this 7 times.

Fair Testing:

To make this test fair I am going to repeat the test 2 times. This will show up any problems with the results. I will also move the arm on the rheostat the same distance each time on the each test I do e.g. 5cm. I will also make sure the rheostat doesn’t get to hot because that will change the outcome of the results, I will stop this happening by turning off the power each time I am not taking a reading from the voltmeter or ammeter

Obtaining Evidence:

The way I will go about obtaining the evidence will be by waiting for the voltage and current to settle down so to be able to read the best possible result.

I was pleased to

...read more.

Conclusion

The things I have found are that ohms law can be broken by a filament light bulb but a fixed resistor will not break ohms law.

Evaluation:  

I think my results are accurate enough to be used as examples. This means they are good enough to go on the internet or in books supporting ohms law.

The procedure went well and there were no problems with the result gathering Which were accurate I think the experiment could be made faire by measuring the length that the arm was moved on the rheostat each time and making sure that you use the same exact  equipment each time as well if you had to record the results over 2 lessons.

The improvements I would make are to have more time collecting more evidence to make the test fair. This would include the improvements I have suggested measuring the distance you move the arm on the rheostat each time and having more time to compete the test but within the same day.  

5/3/2007

10DKJ

...read more.

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

See related essaysSee related essays

Related AS and A Level Electrical & Thermal Physics essays

  1. Using an LDR to detect the intensity of plane polarised light allowed through a ...

    light, there was a problem of reflection: Because the ice cream tub was shiny, it reflected light that was scattered by the light bulb. However, there is a way to rectify it. Since I have a calibration curve, I am able to work out the intensity of light for each angle.

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

    Current is constant, therefore I = 2a c) V = IR V = 2 x 3 V = 6V d) V = IR R(total) = 3 + 4 R(total) = 7? V = 2 x 7 V = 14V 2a)

  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. Sensors cwk. The aim of this coursework is to construct a potential divider circuit ...

    This is because when the object is twice as far away, the area of the object becomes 4 times as big, therefore the energy needs to spread over four times the area; thus 1/4 the light intensity. This relationship can best be understood by looking at a diagram, as below;

  1. Choosing a light source

    it's found when the light diffracts from the centre of the spectra. 2. You need to know M (which is the order i.e. it could be 1,2,3,4, or 5 etc) this value is sometimes given unless you need to find it (calculate it).

  2. Investigating Ohms law

    Therefore they have a low resistance. Some materials are called semi conductors. They conduct electricity, but they also have a high resistance. This is the variable I will be investigating. 4) Temperature: Resistance is also proportional to temperature. Therefore as temperature increases, the resistance also increases.

  1. Heating effects of a current

    faster they will move so the more they will collide so the larger the heat. I predict that the higher the resistant the more the temperature of the water will rise. This is because if the resistant is low the current will pass through the top part of the series

  2. Investigate the effects of two different variables on a solar cell output.

    Variable 2: Distance Distance Another variable that could be investigated with a solar cell is the distance between the solar cell and the light source, and the effect upon the energy transferred to the solar cell when varying distances between the solar cell and light source.

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