measuring electricity ch 6.2

current

the RATE at which electrons flow in a circuit. Measuring in ampere (A) with an ammeter

voltage

the difference in charge between two points. Measured in volts (V) with a voltmeter

resistance

the force with opposes current. Measured in ohm with a ohmmeter

supply voltage

240v of energy is supplied by Australian power points. most appliances do not need the 240V to function

transformer

used to reduce voltage to a manageable voltage for the appliance from the power point. faulty transformers can damage the appliance

batteries

batteries are usually made up of small cells/smaller batteries. Theses cells may be connected to each other with positive and negative points which adds up their voltage.

wet cells

a wet cell conducts electrodes (metal) while being submerged in a liquid electrolyte (solution that conducts electricity)

dry cells

one electrode wrapped in another. They are small and do not leak because they use conducting paste instead of an electrolyte.

photovoltaic cells

concert solar energy into electrical energy. electrons are knocked off silicon crystals by the energy from the sunlight. The knock allows the moment of electrons, creating a current to power appliances

factors to the resistance of a wire

material - low resistance hence why most wires are made of copper, length - longer wires=more resistance, thickness - thicker wires are easier to pass through=less resistance

resistors

are circuit components used to reduce the current flowing in a circuit

variable resistors

components in a circuit that are used to reduce/control the current in a circuit in case a current is too high

good conductors

good conductors allow low resistance. examples are copper and aluminum

bad conductors

examples, tungsten and nichrome. they give off thermal and light energy

insulators

materials with light enough resistance to block the flow of electrons e.g. rubber, wood, plastics