AQA GCSE Physics (9-1) Topic 2a - Circuit Symbols 100% Correct

AQA GCSE Physics (9-1) Topic 2a - Circuit Symbols 100% Correct Switch (Open) Provides a break in the circuit, could be a loose wire which is connected by hand Switch (Closed) Provides a path for the current to flow when closed. Cell Chemical store of energy that provides the potential difference. Long bar is the positive terminal, short bar the negative terminal Battery A number of cells added together in series to form a "Battery". This provides more potential difference. Diode Allows current to flow in one direction only (the direction of the triangle). Has high resistance in the other direction. Usually starts to conduct at about 0.6V Resistor Resists the flow of current and transfers energy to the thermal stores of the surroundings. Often a large piece of metal which is more resistant to current than copper wire. Variable Resistor A component whose resistance can be varied by the investigator. Lamp (Bulb) This is a very thin piece of wire, which resists the current flow and gets red hot transfering energy by lighting and heating to the surroundings. Fuse A thin piece of wire which melts if too much current it drawn through the circuit. This causes a break in the circuit. Voltmeter A very high resistance meter, which is put in parallel across a component and measures the potential difference across the componenent. Ammeter The is a very low resistance meter which is put in series in a circuit loop to measure the current flow through components Thermistor A type of resistor which has a lower resistance when hot. This is the opposite of a normal resistor. Light Dependent Resistor (LDR) This is another type of resistor but in this case it conducts more current when a light is shone upon it.