This KS3 Science quiz challenges you on electrical circuits. An electrical circuit consists of wires, components (like switches and bulbs) and a cell or other source of power. A circuit needs to be complete for electricity to flow through it. If there is a break in the circuit, the electricity cannot pass. The amount of electricity passing through a circuit can be measured in volts and amps. The voltage tells you how much electrical energy there is. The current (number of amps) tells you how much electricity is flowing through the circuit. The amount of current flowing depends on the voltage and the resistance of the components.
There are two types of electrical circuit - series and parallel. In a series circuit, the components are arranged one after the other. If the components in a series circuit are bulbs, the more you add, the dimmer they will be. In a parallel circuit, the bulbs are connected side by side. Each one gets the same amount of energy from the battery and will all be the same brightness. If you add more bulbs in parallel, they will all be as bright as each other.
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You can find more about this topic by visiting BBC Bitesize - Models of electrical circuits
A battery contains two or more cells
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Thomas Edison invented a light bulb that stayed alight. All the previous efforts had only stayed alight for a short while before the filament melted, breaking the circuit
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Switches are used to deliberately break a circuit so that the electricity doesn't flow round it all the time
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Short for ampere
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Most school ammeters are now digital which makes them easier and faster to read
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The energy of the cell is shared between them
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The current splits at a junction in the wires
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It measures the amount of electricity flowing through the circuit or component and therefore needs to be in the circuit rather than being in parallel with it
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The clue is in the wording - you measure voltage across a component
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It is the voltage from the battery or power pack that pushes the current round a circuit. As more bulbs are added to a circuit, it is harder for the battery or power pack to push the current round the circuit. This means that less current flows (so the bulbs would be dimmer than before). To make more current flow you would need to use a higher voltage. To make no current flow, you would need to break the circuit by disconnecting a wire. To keep the current the same as before, you would need to increase the voltage to compensate for the extra bulbs
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