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प्रश्न
Mention the two characteristic properties of the material suitable for making core of a transformer.
उत्तर
Since due to iron core we have two types of losses,
1. Iron lossi.e. energy loss in the form of heat due to the induced eddy current that can be minimized by using thin laminated core.
2. Hysteresis loss due to alternately passing a current in the coil to magnetize and demagnetize the iron core. This can be reduced by using a special alloy of iron core with silicon.
So material with less iron loss and less hysteresis loss is used for making core of transformer.
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.
The adjacent diagram shows a coil would around a soft iron bar XY. (a) State the polarity at the end X and Y as the switch is pressed. (b) Suggest one way increasing the strength of electromagnet so formed.
The primary coil of a transformed has 800 urns and the secondary coil has 8 turns. It is connected to a 220 V a.c. supply. What will be the output voltage?
The input and output voltage of a transformer are 220 V and 44 V respectively. Find: the turns ratio.
Can a transformer be used with direct current source? Give reason.
A 220 V input is supplied to a transformer. The output circuit draws a current of 2.0 A at 440 V. If the ratio of output to input power is 0.8, then the current drawn by primary winding is ______.
Name one electrical device which works on Faraday's law of electromagnetic induction principle.
Define a Transformer.
An iron rod of 0.2 cm2 cross-sectional area is subjected to a magnetising field of 1200 Am-1. If the susceptibility of iron is 599, then the magnetic flux produced is ______.
