Electricity Flashcards
Who made the first battery and in what year?
Volta, 1800
Name 3 other discoveries made using electricity and name the person who discovered it.
1) 1876- Telephone (Bell)
2) 1877- Record player (Edison)
3) 1879- Light (Edison)
What are conductors?
Conductors are materials that electricity (electrons) can flow easily through e.g. electrical wires are made of copper metal.
What are insulators?
Insulators are materials that prevent electricity flowing through them.
Give 2 examples of insulators and one example of where they are used.
Insulators:
1) plastic
2) rubber
Plastic is wrapped around electrical wires.
What is needed for electricity to flow?
A complete circuit
What is the rate at which electricity is flowing called, what is it measured in and what meter is used to meausure it?
Current
Measure in Amperes (Amps)
Measures using a meter called an Ammeter
What is voltage and give an example.
Voltage is the rate at which the parts of a circuit converts the energy of electricity (electrons) to different forms of energy, e.g. the rate at which a light converts electrical energy into light.
What is voltage (potential difference) measured in and using what meter?
Volts
Voltmeter
What is resistance?
A measure of how easy it is for electricity to flow through wires.
Do thin wires have a higher or lower resistance then thick wires?
Higher
The longer the wire is the higher or lower the resistance?
Higher
What units is resistance measured in?
Ohms
What is Ohm’s Law?
Ohm’s Law is a mathematical law which relates current (I), voltage (V) and resistance (R) in a circuit.
State the formula for Ohm’s Law.
Voltage= Current x Resistance V= I x R, or the Law can be written as I= V/R R= V/I
The amount of current flowing is equivalent to…
The voltage applied
If the voltage is doubled then the current will…
double
What is a fuse and what are they used for?
A fuse contains a metal which will melt if too much electricity (current) flows through the wire. Fuses are used to protect circuits and prevent electrical fires.
What is a series circuit?
A series circuit is a circuit that only has one path for electricity to flow. For example, (refer to science revision booklet diagram) each globe is only half as bright as if one globe was used. If one globe blows, so will the other.
What is a parallel circuit?
A parallel circuit is a circuit that has more then one resistor and has multiple paths for electricity to flow.
(Look at diagram)
What is power a measure of?
how rapidly an electrical appliance changed electrical energy into other forms of energy.
What is power measured in?
Watts
What is the equation for power?
Power= Voltage x Current P= V x C
What is a circuit diagram?
A circuit diagram is a map of a circuit using standard symbols to represent different components.
What is electro- magnetism?
A magnetic field surrounding a wire carrying an electric current.
Give two examples of objects that use electro- magnetism?
- Bells
- Circuit breakers
What is direct current (DC)?
Electricity that flows one direction through the circuit. Batteries produce direct current.
What is alternating current (AC)?
The direction of current flow through the circuit is changed 10 times per second (50 Hertz).
