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प्रश्न
Mention the two characteristic properties of the material suitable for making core of a transformer.
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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
Derive an expression for ratio of e.m.f.s and currents in terms of number of turns in primary and secondary coil.
Draw a labeled diagram of a step-down transformer.
State the principle of the step-down transformer and its working.
The following diagram in Fig.10.42 shows a coil of several turns of copper wire connected to a sensitive centre zero galvanometer G near a magnet NS. The coil is free to move in the direction shown in the diagram.
(i) Describe the observation if the coil is rapidly moved.
(ii) How would the observation be altered if (a) the coil has twice as many turns (b the coil was made to move three times as fast?
Given the input current 15 A and the input voltage of 100 V for a step-up transformer having 90% efficiency, find the output power and the voltage in the secondary if the output current is 3 A.
Describe briefly and two energy losses, giving the reasons for their occurrence in actual transformers ?
Name three losses of energy in a transformer. How are they minimized?
Find out the phase relationship between voltage and current in a pure inductive circuit.
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 ______.
In an ideal transformer, the turns ratio is `N_p/N_s = 1/2`. The ratio Vs : Vp is equal to (the symbols carry their usual meaning):
