Physics Coursework: Resistance in a circuit

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Physics Coursework

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Resistance makes it harder for the current to flow in a circuit. Resistance occurs when the free electrons collide with the atoms. The greater the resistance is, the smaller the current will be. Resistance is measured in ohms (Ω). To work out the resistance of any given voltage, we must use Ohm's Law. Ohm's Law states that the current through a metallic conductor, like a wire, is proportional to the potential difference (Voltage), when at a constant temperature. The equation is this:

Electrical current only flows if there are charges that can move freely. Metals contain mobile electrons that can flow through the metal. This is why electric current flows well in metals. Current in a circuit flows from positive to negative.

If the voltage is increased more current will flow. Voltage is the electrical pressure that pushes the current around the circuit. It is measured in volts. The total voltage supplied is shared between the various components.

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Resistance is anything that slows the flow of electrons (current) down in a circuit. Resistance is measured in ohms, W. As resistance is increased less current will flow. The total resistance in a series circuit is sum of all the resistances

Ohm's law is the mathematical relationship between the voltage, current and resistance in an electric circuit. This law states:

Voltage (V) = amps (I) x Ohms (R)

V=IR

The relationship between heat and resistance is demonstrated by the fixed resistor and filament light bulb experiments. When a filament light bulb is used more heat is created than when a ...

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