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

The factors affecting the current flow through a conductor at a constant temperature.

Extracts from this document...

Introduction

Brief

I need to investigate the factors affecting the current flow through a conductor at a constant temperature.

Introduction

Resistance is a force found in currents that opposes the flow of electrons around a circuit. When this occurs energy is needed to push the charged particles around the circuit. The circuit itself can resist the flow of particles if the wires are either very thin or very long. E.g. the filament across an electric bulb is quite thin as needs to resist the flow of particles for the bulb to glow. Resistance is measured in Ohm’s because George Ohm discovered it.

Plan

As I need to investigate the factors affecting current in a circuit I need to vary something connected to current. The ideal choice is Ohm’s law (resistance = voltage/Current) because voltage and resistance are easily changed to vary the current. Ohm’s law is sometimes written like this:

image00.png

V = Voltage

C = Current

R = Resistance

Current is the flow of electrons in a circuit. This is what an ammeter measures. There are 2 types of ammeter, digital and analogue. Digital readers are easier to read because the current is displayed as a number.

...read more.

Middle

Reliability

I know that the results will be accurate because having a second experiment will check them. Any anomalous readings will hopefully be averaged out and will not have a significant impact on the final result.

Measurements

The measurements will be recorded in ohm’s, volts, and amp’s and also in degrees.

Proposed Range

I will hopefully get a range of 0-1 amps during the experiment.

Hypothesis

I predict that when the resistance in the circuit increases the current and the voltage will decrease, according to Ohm’s law (resistance = voltage/Current).

As the resistance increases there will be more ‘hurdles’ for the electrons to conquer as they travel around the circuit, and this is why the voltage and current will decrease. As long as the temperature remains constant this hypothesis will be accurate. The resistance will be proportional to the current.

Obtaining Evidence

...read more.

Conclusion

If I had the chance to conduct an experiment like this again I would change the voltage as well whilst keeping the resistance and current the same to prove Ohm’s law correct. I would then be able to cross-reference the results and make a full investigation of the brief. The method for the next experiment is shown below.

  1. Set up the circuit as shown in the original circuit diagram.
  2.  Prepare a results table to record the data from the circuit. It should include voltage and resistance readings. The resistance will be calculated as before.
  3. Instead of a variable resistor it may be a prudent decision to use a fixed resistor. The results will be taken more accurately and will keep it a fair test.
  4. Repeat each part of the experiment twice, to gather average readings and to filter out any mistakes.
  5. Draw a graph of the results to compare with the graph of current against voltage.
  6. Draw another conclusion and evaluate the investigation, stating how it worked and what went wrong.

I would have also liked to make the recordings with an analogue reader to test the difference in accuracy between an analogue reader and a digital reader. This would have also been an interesting investigation.

...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. Investigate how the temperature affects the resistance of a thermistor.

    in obtaining the data I found that the data I did obtain wasn't as accurate as it could have been and so as a result of this I had a few anomalies.

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

    * The crocodile clips may not have been placed on the exact point for the length required. The length could have been greater or less than the required length, giving a higher or lower resistance. * Analogue voltmeters and ammeters do not give a high degree of accuracy due to manmade reading errors.

  1. To investigate how the temperature affects the resistance of a thermistor.

    0C 500 680 472 40 0C 412 370 394 *RETEST - original resistance = 672? Temperature of Thermistor (0C) Average Resistance (?) 100C 1073? 150C 851? 200C 764? 250C 691? 300C 636? 350C 551? 400C 392? Graph: (on following page)

  2. silicon project

    In 1811 Gay Lussac and Th´┐Żnard probably prepared impure amorphous silicon through the heating of potassium with silicon tetrafluoride. In 1824 Berzelius prepared amorphous silicon using approximately the same method of Lussac. Berzelius also purified the product by repeatedly washing it.

  1. Relationship between the current and voltage.

    For the light bulb, the resistance will vary and will never be constant. As this is the case, I expect a graph with a curve, and positive gradient. The graph will start to curve more, and have a steeper gradient the greater the voltage, and current are.

  2. How the resistance of a thermistor changes with temperature keeping the current constant and ...

    Also I have to find the time it takes to complete a trial of the experiment so I can work out how many readings it is possible to take in the given time. Method I need to set up the experiment in the way (shown later)

  1. To discover whether a filament lamp is an ohmic conductor.

    current flowing through it, in amperes(I) As the current passing through the circuit is increasing less than an ohmic conductor would due to the obstructing atoms of tungsten, and the voltage is increasing at the same amount as it would in an ohmic conductor the resistance will therefore increase making a curve in the graph.

  2. Investigating how temperature affects the resistance in a wire

    -They can be mixed together to create alloys of slightly different properties (e.g. Steel) These properties can be affected by their surroundings, the five factors that can affect metals are; heat, radiation, a magnetic field and the flow of electrons/ current.

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