Tramsformers Flashcards
What happens is a magnet is moved into a coil of wire?
A potential difference is up induced across the ends of the coil
What does an alternating current in a primary coil produce?
It produces a changing magnetic field in the iron core and hence in the second coil. This induces an alternating potential difference across the ends of the secondary coil
In a step-up transformer the potential difference across the secondary coil is:
Greater than the potential difference across the primary coil
In a step-down transformer the potential difference across the secondary coil is:
Less than the potential difference across the primary coil
What frequency do switch mode transformers work at?
At a high frequency, such as 50 Hz and 200 Hz
What is the difference between a switch mode transformed and a traditional transformer?
Switch mode transformers are much lighter and smaller than transitional transformers, working from a 50 Hz mains supply
Advantage of a switch mode transformer
They use very little power when they are switched on but no load is applied
Describe a transformer
It consists of two could of insulated wire, called the primary coil and the secondary coil. These coils are wound to the same iron core. When an alternating current passed through the primary coil, it produces an alternating magnetic field in the core
What type of core does a switch mode transformer have?
It has a ferret core
Why is the core of a transformer mare it iron not copper?
Iron can be magnetised
Hat happen is a 1.5V cell is used as the supple for the primary coil?
The transformer will not work,as it requires an ac supple. A cell supplies dc
Why is a transformer used to step-up the potential difference from a power station?
So that the electrical energy can be transmitted to a high pd, reducing the energy waste in ten cables
What happens is an electrical conductor ‘cuts’ through a magnetic field?
A potential difference is induced across the ends of the conductor
