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प्रश्न
Explain the construction and working of the transformer.
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उत्तर
Construction: It consists of two coils of primary and secondary coils insulated from each other and wound on a soft iron core as shown in fig. (a). Input is applied across the primary coil, and output is taken across the secondary coil.
Notations:
P1, P2: Primary coil
S1, S2: Secondary coil
There are two types of transformers:
- Step-up transformer: In this, the number of turns in the primary coil is less than the number of turns in the secondary coil. The primary coil is made up of thick wire, and the secondary coil is made up of thin wire.
- Step-down transformer: Here the number of turns in the primary coil is greater than that in the secondary coil. The secondary coil is made up of thick wire, and the primary coil is of thin wire.
Working: When an AC voltage is applied to the primary coil, the current through the coil goes on changing. Hence the magnetic flux through the core also changes. As this changing magnetic flux is linked with both coils, an emf is induced in each coil. The amount of magnetic flux linked with the coil depends upon the number of turns of the coil.
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संबंधित प्रश्न
A transformer converts 240 V AC to 60 V AC. The secondary has 75 turns. The number of turns in primary are _______.
(A) 600
(B) 500
(C) 400
(D) 300
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Mention various energy losses in transformer device
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……… energy is converted into …………energy by an electric motor.
Name the phenomenon ?
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(i) Describe the observation if the coil is rapidly moved.
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Mention the two characteristic properties of the material suitable for making core of a transformer.
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State the factors on which the frequency of the alternating e.m.f. depends.
Name the principle on which functioning of a transformer depends.
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State the mathematical relation between a number of turns in the primary coil to a secondary coil in the step-up transformer.
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What is Transformer?
Devices which is used to convert high alternating current to low alternating current is ______.
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For an ideal step-down transformer, the quantity which is constant for both the coils is ______.
Read the following paragraph and answer the question:
Long distance power transmissions
The large-scale transmission and distribution of electrical energy over long distances is done with the use of transformers. The voltage output of the generator is stepped up. It is then transmitted over long distances to an area sub-station near the consumers. There the voltage is stepped down. It is further stepped down at distributing sub-stations and utility poles before a power supply of 240 V reaches our homes.
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Explain why core of a transformer is always laminated.
For what purpose are the transformers used?
In an ideal transformer, the turns ratio is \[\frac {N_p}{N_s}\] = \[\frac {1}{2}\]. The ratio Vs : Vp is equal to (the symbols carry their usual meaning) ______.
An ideal transformer converts 170 V a.c. to 1.70 KV a.c. to transmit a power of 3.4 KW. If primary coil has 500 turns then alternating current in secondary coil is ______.
