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

To measure resistance and verify ohms law

Extracts from this document...



AIM-To measure resistance and verify ohms law


Current is the rate of flow of charge. Electrons carry the charge, which they get from the battery around a circuit. Current flows from negative to positive, even though we usually say it flows from positive to negative, as this is conventional current.

There are two types of circuit: - Series circuit.

     - Parallel circuit

A series circuit is when the electrons have only one choice of path. This circuit can have an infinite number of components as long as they are all in series. However if bulbs are included in this circuit, then the voltage is shared between them.

In parallel circuits the electrons have more than one choice of path. The current is shared in parallel circuits but the voltage stays the same.

The current is measured in amp’s (A) by an ammeter. How much energy each electron has gained from the battery, is known as voltage. Voltage is measured in volt’s (V) by a voltmeter. When voltage increases, current also increases. This is because the electrons are given more energy so they will be able to flow through the wire faster.

A resistor controls the current. There are two types of resistor:

  • Fixed and
  • Variable

A fixed resistor cannot change its value. However a variable resistor can, it is used in remote controls to alter the volume.

...read more.































Potential Difference (Voltage) and Current Measurement for a Filament Bulb.

Claremont High School Physics Department.


                                        CURRENT (A)



Black Resistor

Red Resistor

Blue Resistor

Test 1

...read more.


The anomalous results that I have obtained could be the result of inaccurate or faulty equipment. Another reason could be that the meters were analogue meters and therefore had to be read by the human eye so mistakes in the accuracy of the readings could have easily occurred. There could have been a slight temperature increase as the power pack heated up. The blue resistor had a few results, which did not fit in a straight line. As it was the last resistor to be tested the wire could have heated up during the course of the experiment, making the readings less accurate.

To improve the experiment digital meters could have been used to avoid inaccurate readings by the human eye. Also the wire could be given time to cool down in between each test so inaccurate results could be avoided.

Sources of Information

* CD- ROM - Encarta 2000

* SPG GCSE Double Science Physics Revision Guide

  2001 Edition

* Potential Difference (Voltage) and Current Measurement for a Filament Bulb.

Claremont High School Physics Department.

...read more.

This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism 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 GCSE Electricity and Magnetism essays

  1. Resistance Of a Wire - Ohm's law.

    Method The two dots ( ) represent the crocodile clips that were placed at the ends of the required length of wire. 1. One metre length of 0.4mm diameter "constantan" (a metal alloy) wire is fixed to a metre rule.

  2. Ohms Law.

    * Do not switch on the power pack when there is no resistant wire and do not turn the power supply up too high because normal laboratory wires may melt Background knowledge Using a circuit such as this one on the left, an important general relationship can be seen.

  1. Experiment to Verify Ohm's law - Resistance Course Work.

    The number of cycles per second is called the frequency of the AC. This alternating current is talked about in the paragraphs above. Apparatus 100cm of constantan wire Ammeter Voltmeter Battery Crocodile clips Diagram Method 1. The apparatus was set up as in the diagram above and the voltage across the wire was set to be 3Volts.

  2. Ohm's law.

    This shall be repeated three times for each length of wire to ensure that the test is fair. Then the crocodile clips shall be moved by another ten centimeters from the end of the wire. Another three readings shall be taken and the crocodile clips shall be moved another ten centimeters.

  1. charles law

    Table 1 Table to show oscillation, length, time, periodic time and frequency for a wood meter rule. Oscillation length(m) 1st time(s) 2nd time(s) Mean time(s) Periodic time = time Oscillation Frequency (hertz) = 1 Periodic time 10 0.9 6.71 6.62 6.62 0.66 1.52 10 0.85 5.46 5.01 5.24 0.52 1.92

  2. Ohm's Law Investigation

    The resistance of a conductor (in this case the wire) is the ratio of the potential difference across it, to the current flowing through it. A resistor does not stop current from flowing; it just slows down the rate at which it flows. Charge (Q), flow (V) and resistance (R)

  1. The Car Crisis.

    PV cells are even being used to provide electricity for homes, villages, and businesses. Some electric utility companies are building PV systems into their power supply networks. Although the PV cells used in calculators and watches are tiny-less than a half inch (1.2 centimeters)

  2. Investigating The Characteristics Of A Filament Lamp

    lamp heats up more quickly, and therefore causing the filament to also glow more quickly. To increase the resistance in the wire, and also the temperature, the filament is made out of a metal, a good conductor of electricity, the cross-sectional area of the wire is as small as possible, in order to increase the resistance.

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