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# How does a transformer work?

## 28 Apr How does a transformer work?

Today in physics tuition, we will learn about a very important machine. Have you ever heard of transformers? You may have as transformers are necessary to supply electricity to your locality. Do you know how a transformer works? You will find in today’s physics tuition the working principle of transformers. Your physics tuition is always there to answer all your queries.

A transformer is a very common and efficient electric machine. Huge transformers are used in power houses and smaller ones in our radio sets.
It is mainly used to increase or decrease electric voltage or current. To understand its working we have to keep the fact in mind that when electric current passes through a coil of wire it behaves like a magnet. Similarly, as long as a wire keeps on cutting a magnetic field, an electric current is generated in it. The product of voltage and current remains more or less constant. It is called the power. When voltage increases current decreases and vice versa. In alternating currents the voltages, currents and magnetic fields are changing from moment to moment.
It is because of this reason that a transformer works only on alternating currents. This whole phenomenon is called electromagnetic induction. This principle is of great importance in electrical engineering and many of its machines working on this principle. The name of the famous British scientist, Michael Faraday is closely associated with the electromagnetic induction.

A transformer usually consists of a laminated core of soft iron and two coils are wound around this core. The number of turns of wire in the two coils is different. We need electric power to one coil which is called the primary coil. We take electric power from the other coil which is called the secondary coil. When the number of turns of wire in the secondary coil is more than in the primary, we get a higher voltage. Such a transformer is called a step-up transformer. On the other hand, when the number of turns in the secondary coil is less, we get a lower voltage. We then get a step-down transformer. The same transformer can be made to function either as a step-up or a step-down transformer. Stepping –up or stepping-down depends on the turn ratio of the coils.

There are many types of transformers and they are used for different purposes. They handle power from a fraction of a watt to millions of watts. They differ greatly in construction, materials, size, power handling capacity etc. We hope you enjoyed this lesson from physics tuition. We will be back with more such interesting findings in our next physics tuition.

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