Electricity and Magnetism Flashcards
Define and give examples of static electricity. (2)
Static electricity is the build-up of electrons in one place. Examples include lightning and when you rub a balloon against your hair.
How does the flow of current alter from the flow of electrons? (1)
Current flows from positive to negative and electrons flow from negative to positive (they go in different directions).
Distinguish between an electrical conductor and an electrical insulator. (1)
An electrical conductors allows electrons to pass through it; and insulator does not.
Identify the common circuit symbols and draw a circuit diagram correctly.
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Compare series and parallel circuits. (2)
In a series circuit, all the components are in one loop; in a parallel circuit, there are multiple loops that components can be in.
Define voltage and state its units. (2)
The voltage (or potential difference) of a supply is a measure of the energy given to the electrons in a circuit. It is measured in volts (V).
Define current and state its units. (2)
Electric current is the flow of electrons. It is measured in amperes/amps (A).
Define resistance and state its units. (2)
Resistance is the opposition in an electrical component to the current flowing through it. It is measured in ohms (Ω). Conductors have relatively low resistance compared to insulators.
What is an LDR and how does it work in a circuit, in low or strong light? (2)
An LDR is a light dependent resistor. In low light, it doesn’t work well, but the resistance increases with the light.
What is a diode? (1)
A diode is an electronic component that will only allow electric current to pass through it in one direction.
Explain what a light emitting diode (LED) is and how it works. (2)
An LED is a diode that emits light when current passes through it.
Understand the role of switches. (1)
Switches can be either on or off. When they are on, or closed, electric current may flow through, but when they are off, or open, electric current cannot flow.
Describe some common properties of magnets. (4)
They are usually made of iron, they have two ends called magnetic poles, they can also repel other magnets and they can attract some materials.
Describe how to make an electromagnet including how to make it stronger. (2)
An electromagnet can be made by coiling a piece of wire and running current through it. It can be made stronger by adding an iron core and/or passing more current through it.
List some common uses of electromagnets. (4)
MRI scanners, speakers, headphones and motors.
