Electric Cells as energy systems Flashcards
What is a cell?
A cell is a chemical systemin which certain chemical reactions can cause the flow of electric charge through an external circuit.
What is a system?
A set of parts that work together to carry out an overall function
What is an electrode?
The terminal or conductor through which an electric current enters or leaves a cell.
What is an electrolyte?
A solution that can conduct electricity
What is voltage?
The amount of energy a cell gives to an electron (measured in volts-V) We use a voltmeter to measure this.
What is a battery?
Two or more cells connected together.
How do you use a voltmeter?
Must be connected in parallel to the component you are measuring the voltage for, The positive terminal of the voltmeter is connected to the positive terminal of the component and the negative terminal of the voltmeter must be connected to the negative terminal of the component
How do you use an ammeter?
The ammeter can be connected at any point of the circuit, the positive terminal of the ammeter must be connected to the positive terminal of the battery of cell and the negative terminal of the ammeter must be connected to the negative terminal of the battery or cell.
What is an ammeter?
An instrument used to measure the size of the current.
What is current?
The flow of charges through a circuit. (measured in amperes - A)
What is a transformer?
A device that increases or decreases voltage
What is a turbine?
A machine that converts different forms of energy into electrical energy
What is nuclear energy?
An energy source found in the atoms of chemical elements such as uranium
What is nuclear power?
Electricity made using energy released from atoms. It is made from uranium. There is a station in Cape Town, Koeberg
What is radiation?
A form of energy released by radioactive fuels
What is nuclear fission?
When the nucleus of an atom is split in 2
What does the term radioactive mean?
Gives off radiation energy from the breakdown of an atom’s nucleus
What is electrical power?
The rate of electrical energy supply
What are watts?
The unit in which electrical power is measured (kilowatts- a thousand watts)
How do you measure watts?
Power = work (J) divided by time (s)
How do you measure the cost of electricity?
Cost = power rating (W or kW) x the number of hours an appliance is used x the unit price of electricity (eg 50c) Cents divided by kWh
What is the National Grid?
A network of electricity cables and pylons all over South Africa. It is an electrical system that supplies electricity
What is an earth wire?
Protects people from electric shock for providing a low resistance path for electricity to flow to the ground
Series
The current strength in a series circuit is the same at any point of the circuit.
Parallel Circuit
The voltmeter reading across each of the resistors = the voltmeter reading across the battery
