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प्रश्न
A transformer lowers e.m.f. from 220 V to 15 V. If the number of turns in primary are 3520, how many turns are in the secondary coil?
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उत्तर
We know that `"E"_"s"/"E"_"p" = "N"_"s"/"N"_"p"`
or `10/220 = "N"_"s"/3250`
`"N"_"s" = (3520 xx 15)/220 = 240`
Number of turns in secondary are = 240.
संबंधित प्रश्न
The teachers of Geeta’s school took the students on a study trip to a power generating station, located nearly 200 km away from the city. The teacher explained that electrical energy is transmitted over such a long distance to their city, in the form of alternating current (ac) raised to a high voltage. At the receiving end in the city, the voltage is reduced to operate the devices. As a result, the power loss is reduced. Geeta listened to the teacher and asked questions about how the ac is converted to a higher or lower voltage.
1) Name the device used to change the alternating voltage to a higher or lower value. State one cause for power dissipation in this device.
2) Explain with an example, how power loss is reduced if the energy is transmitted over long distances as an alternating current rather than a direct current.
3) Write two values each shown by the teachers and Geeta.
State two ways through which the strength of an electromagnet can be increased.
For what purpose are the transformers used? Can they be used with a direct current source?
How are the e.m.f in the primary and secondary coils of a transformer related with the number of turns in these coils?
In a transformer, the frequency of A.C. voltage ______.
The input and output voltage of a transformer are 220 V and 44 V respectively. Find: the turns ratio.
What is the ideal transformer?
State the factors on which the frequency of the alternating e.m.f. depends.
A transformer is used ______
Explain why core of a transformer is always laminated.
