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Investigating Electricity.

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GNVQ Science Unit 1 and 3

Investigating Electricity

Section A: Voltage, Current and Resistance and Ohm’s Rule

Firstly, to being this assignment I will be introducing what exactly Ohm’s rule is and what voltage, current, and resistance is and how they are measured.

  • Resistance: - resistance is a measure of the degree to which an electrical component opposes the passage of current. It is the ratio of the potential difference (i.e. voltage) across an electric component (such as a resistor) to the current passing through that component: R is the resistance of the component. If the resistance of a material is low then charges can pass through it easily.

(Resistance = Voltage ÷ Current)

  • Current: - Electric current is the rate of charge flow past a given point in an electric circuit, measured in coulombs/seconds which is named amperes. In most DC electric circuits, it can be assumed that the resistance to current flow is a constant so that the current in the circuit is related to voltage and resistance by Ohm’s law.

(Current = Number of Coulombs per second) & (Unit of current = Amps)

  • Voltage: - Voltage is a measure of the energy required to move a charge from one point to another. A difference in the amount of electric charge between two points creates a difference in potential energy, measured in "volts," which causes electrons to flow from an area with more electrons to an area with fewer, producing an electric current.

(Voltage = Joules per Coulomb = Volts)

  • Ohm’s Rule: - Ohm's law, named after its discoverer Georg Simon Ohm, states that the potential difference (or voltage drop V) between the ends of a conductor (for example, a resistor R) and the current, (I) flowing through R are proportional at a given temperature: where V is the voltage and I is the current; the equation yields the proportionality constant R, which is the electrical resistance of the device.

Aim: My aim in this coursework will be to do some experiments

          To measure electrical circuits

I will be carrying out an experiment and the following

Equipments will be needed for me to carry out this experiment:

  • 1 Power Pack
  • 1 Voltmeter
  • 1 Bulb
  • 2 Resistors
  • 1 Ammeter
  • 2 Wires (1 black, 1 red)
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In the experiment I will be measuring the voltage and the current; I will vary the voltage from 0 volts to 10 volts and take the current reading from the ammeter.

Some devices let a large current through them. These devices have a low resistance to the flow of current. A device with a high resistance allows less current to flow through it when the same voltage is applied. Resistors pass a certain amount of current for a given voltage. High value resistors let a small current pass, and a low value resistor allow a large current to pass. Standard resistors have their resistance clearly marked and some value showing the maximum current allowed without overheating.

I will now be carrying out my experiment with the resistor.

The table of my results from this experiment with the resistor are listed below; in the table I included the volts, milliamps and the amps.

Resistor Table:



Amps (Current)


0 mA



0.44 mA



0.97 mA



1.64 mA



2.15 mA



2.71 mA



3.38 mA



3.74 mA



4.19 mA









Conclusion from Resistor Results:

From looking at the table that I have produced from my

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And the last test was to see if the little light lit every one-second, and it also passed this test.
  • Suggestions of any possible improvements.

Answer: The only improvement that I could suggest would be to do a different type of circuit such as a parallel circuit and see what we come out with, we could also try using different components in our device and another idea would be to increase the current, but not to high. But the only improvement I can definitely go with would be to try a parallel circuit.

  • A comparison of your project to how it might be done by a professional company.

Answer: I am about to compare the way my project was done to the way it          would’ve been done in a professional company.

In a professional company they would not have constructed their electronic device using the same method that I used when I was doing mine, in a professional company they use robots to make the electronic devices and they also have quality control systems to test the circuitry. They also have printed circuits when it is done in Proffesional Company and they also have automatic constructing techniques when constructing the electronic devices in a professional company, the device is passed along through steps where more parts will be added on after each step and this method is a lot quicker than the method that I used.


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