National 4 Electronics Flashcards
How is an electromagnet made?
An electromagnet can be made by winding insulated wire around an iron core and passing current through the wire
What are applications of electromagnets?
Electric bells and relay switches
What is a transformer made up of?
A transformer consists of two coils wound around the same iron core
How do transformers work?
Transformers use a.c. in the primary coil to creat a constantly changing magnetic field. This causes a voltage across the secondary coil. The size of the voltage depends on the number of turns in the coils. If the secondary coil has more turns than the primary coil, it will have a bigger voltage
What are transformers used for?
Transformers are used to “step up” or “step down” voltage in electricity distribution systems to reduce energy losses in transmission lines. Transformers are also used in adapter plugs for electonic equipment
What does a generator do?
A generator transfers kinetic energy into electrical energy using electromagnetism
How is electrical energy generated?
To generate electrical energy, a coil of wire must be near a changing magnetic field. This can be done by; moving a coil near a magnet or moving a magnet near a coil
How does a fossil fuel power station work?
- The fossil fuel burns, producing heat energy
- The heat boils the water, turning it into steam
- The steam turns the turbine
- The turbine drives the generator, producing electrical energy
What does a fuse do?
A fuse protects the flex from overheating. It melts and breaks the circuit if the current gets too high
How is a magnetic field made?
A wire with a current flowing in it produces a magnetic field
What is the difference between digital and analogue electronic devices?
Digital electronic devices are either ON or OFF whereas analogue components can produce a range of inputs or outputs
