Unit 2 - Electricity Flashcards
What is the function of the cell / battery?
Provides the circuit with a source of potential difference. A battery is two or more cells.
What is the function of the Switch?
Turn the circuit on (closed) and off (open)
Fixed resistor
A resistor limits the flow of current. A fixed resistor has a resistance that it cannot change.
Variable Resistor
A resistor witha slider that can be used to change its resitance. These are often used in volume controls.
Thermistor
The resistance of a thermistor depends on its temperature. As temperature increases, resistance increases.
Light-emitting diode (LED)
A diode that emits light when a current passes through it.
Ammeter
Used to measure the current in a circuit. It is connected in series with other components.
Voltmeter
Used to measure potential difference of an electrical component. Connect in parallel with the relevant component.
What part of the circuit provides energy?
The cell
Which part of the circuits transfers energy out?
The components
How do you work out potential difference? (from a diagram)
Voltage per cell x Number of cells
How does the cell work?
Drives electrons around the circuit by doing work on the electrons to overcome repulsive electrostatic force.
What is the word equation for potential diffrence?
Potential Difference = Work done / Charge
What is the measurement for charge?
Coulombs (C)
What is the mathematical equation for potential difference?
V = W / Q
