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प्रश्न
Draw a labelled diagram of a step-up transformer and explain how it works.
उत्तर
Step-up transformer: The step-up transformer is used to change a low voltage alternating e.m.f. to a high voltage alternating e.m.f. of same frequency.
Working: When the terminals of primary coil are connected to the source of alternating e.m.f., a varying current flows through it which also produces a varying magnetic field in the core of the transformer. Thus, the magnetic field lines linked with the secondary coil vary and induce an e.m.f. in the secondary coil. The induced e.m.f. varies in the same manner as the applied e.m.f. in the primary coil varies, and thus, has the same frequency as that of the applied e.m.f.
The magnitude of e.m.f. induced in the secondary coil depends on the 'turns ratio' and the magnitude of the applied e.m.f.
For a transformer,
`("E.m.f. across the secondary coil" ("E"_"s"))/("E.m.f. across the primary coil"("E"_"p")) = ("Number of turns in the secondary coil" ("N"_"s"))/("Number of turns in the primary coil" ("N"_"p"))` = Turns ratio (n)
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संबंधित प्रश्न
Draw a labelled diagram of a device you would use to transform 200 V a.c. to 15 V a.c. Name the device and explain how it works. Give its tow uses.
- Complete the following diagram of a transformer and name the parts labelled A and B.
- Name the part you have drawn to complete the diagram in part (a).
- What is the material of this part named above?
- Is this transformer a step up or step down? Give reason.
State whether true or false. If false, correct the statement.
In a step down transformer the number of turns in primary coil is greater than that of the number of turns in the secondary coil.
Differentiate step up and step down transformer.
A portable radio has a built in transformer so that it can work from the mains instead of batteries. Is this a step up or step down transformer? Give reason.
The transformation ratio in the step-up transformer is ______
A transformer is used to change a high alternating e.m.f. to a low alternating e.m.f. of the same frequency.
Identify the type of transformer used for the above purpose.
A transformer is used to change a high alternating e.m.f. to a low alternating e.m.f. of the same frequency.
State whether the turns ratio of the above transformer is = 1 or > 1 or < 1.
Name the device used to transform 12 V a.c. to 200 V a.c.
Name the coil of which the wire is thicker in a step down transformer. Give reason to your answer.
