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

Ohm’s Law Investigation

Extracts from this document...

Introduction

Ohm’s Law Investigation

Introduction: In the following experiment, I predict that the filament

bulb in which we are testing, on will not obey ohm's law. Their are many

factors which make me believe this, such as the temperature of the bulb.

If the filament bulb DID obey Ohm's Law, then the temperature would remain

constant, meaning there would be resistance.

When I think of a light shining, the temperature does not stay the same.

Therefore I believe that the light bulb will not obey Ohm's law.

The formula for Ohm's law  is:

RESISTANCE = pd            or        R = V

           current                       I

The current through a wire is proportional to potential difference (voltage

across the wire) providing the temperature does not change - (which I predict

it shall).

CHANGE IN TEMPERATURE = CHANGE IN RESISTANCE

...read more.

Middle

so no water reaches the wires. We must also check our readings on the Voltmeter - incase any

explosion occurs, and we must check that the wires are carfully fixed in to place. It is also

important, for long hair to be tied up and to wear lab coats.

APPARATUS:

Power Supply (p.s.u) ----- This is the main source of power used in the experiment.

Voltmeter --- this measures the potential difference ACROSS a component (in volts)p.d

Ammeter ---  The measures the current through a component (in amps)

Filament Bulb --- This is what we are testing for Ohm's law with.

Wires --- The experiment is not possible without the use of the wires - in which the current

will flow.

We set up the circuit shown in the diagram above.

...read more.

Conclusion

that it did not obey Ohm's law. I know about Ohm's law from the theory:

A CURRENT THROUGH I WIRE IS PROPORTIONAL TO POTENTIAL DIFFERENCE ACROSS THE WIRE, PROVIDING THE TEMPERATURE REMAINS

CONSTANT.

EVALUATION:

I think the results were overall accurate. We did repeat them twice aswell as including the trail run; but we still could have

been more accurate. We only recorded the Observations once. We could have been more accurate if we did it at least twice. We had no

anomalous results. I think the safety was good and it overall went well - maybe a lack of detail. I think the conclusion is reliable.

To help us on Ohm's law, we could have included more tests on other things for Ohm's law as a simalar investigation - but I was overall

pleased.

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

    Make sure that the voltmeter and the ammeter are connected into the circuit correctly. xiii. Once your circuit has been checked switch on the power supply. xiv. Check if the circuit works, and the ammeter and voltmeter is giving you write values.

  2. A2 Viscosity investigation

    these results and error values will probably contain the actual result somewhere in there range bout where is uncertain due to the high amount of inaccuracy although I suspect it to be more close to the actual result as the error values are maximums.

  1. Choosing a light source

    Looking at all of my calibration graphs, I could now conclude and say that it agrees with my predication (hypotheses) (they all tend to fit the pattern), as I predicted the higher the power the greater intensity, and the less intensity the lower the brightness.

  2. To find which of the circuits, shown below, are most suitable to measure a ...

    As I continued on with my calculations in exactly the same manner, I obtained the following readings: Circuit One Value specified on Resistor (?) Value Obtained due to calculations (?) Change in Resistance (?) Percentage Change (%) 50 49.95 0.05 0.10 100 99.80 0.20 0.20 500 495.05 4.95 0.99 1000

  1. Investigating how temperature affects the resistance in a wire

    k*the temperature (where k = the gradient). Apparatus: -5 lengths of standard insulated wire approximately 40 cm in length (used to connect the batteries to the multimeters and the steel) -Two digital multimeters (used to measure the volts and the amps)

  2. Magnetism Investigation

    If the currents are in the same direction, the conductors experience an attractive force, while oppositely directed currents will produce a repulsive force. This equation is valid only for infinitely long conductors. However, if the separation d between the conductors is very much less than the length of either conductor, then the error in the equation is negligible.

  1. To investigate the relationship between current and potential difference (ohm’s law).

    through a metal wire is 'proportional' to the potential difference (V) across it, if the temperature is constant. Ohm's law, V=IR says that for a certain current (charge flowing at a certain rate), there will be a greater voltage across the wire if it has more resistance.

  2. Resistance Investigation

    Below, a variable resistor is being used to control the brightness of a bulb. The variable resistor contains a long coil of thin nichrome wire. Sliding the control to the right puts more resistance into the circuit, so the bulb gets dimmer.

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