Please enable JavaScript.
Coggle requires JavaScript to display documents.
electricity and resistance - Coggle Diagram
electricity and resistance
introduction to circuits
Circuit diagrams are used to show how electrical components are connected in a circuit.
Individual circuit components are represented using circuit symbols.
Ammeters are used to measure the current flowing through components. Voltmeters are used to measure the potential difference across components.
fruit cells
The chemistry behind the fruit cell is that zinc is more reactive than copper which means zinc loses electrons more easily than copper. As a result, oxidation occurs in the zinc metal strip and zinc metal loses electrons which then become zinc ions.
resistance
Resistance (R) is a measure of how difficult it is for current to flow. Resistance is measured in units called ohms (Ω).
The amount of current flowing in a circuit is affected by the resistance of that circuit.
Each component in a circuit has a resistance.
Resistance can be calculated using the equation: Resistance = potential difference ÷ current
ohms law
voltage = current times resistance = v=ir
electro mahnets
An electromagnet uses an electrical current to generate a magnetic field.
There are three ways to strengthen an electromagnet:
increasing current
increasing the number of turns of the coil
adding an iron core
An electromagnet with a permanent magnet can be used to make motors and loudspeakers.
energy and power
power = current × potential difference
power (P) is measured in watts (W)
current (I) is measured in amps (A)
resistance (R) is measured in ohms (Ω)