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प्रश्न
Mention two main sources of power loss in real transformers.
उत्तर
Two causes of energy loss in a transformer are:
- Heat loss due to copper: It is the loss of heat energy over the resistance of the copper winding in the primary and secondary coils.
- Hysteresis loss: The loss caused by the heating of the core as a result of its repetitive magnetization and demagnetization cycles when an alternating emf is applied across the primary coil.
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संबंधित प्रश्न
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?
The secondary windings of a transformer in which the voltage is stepped down are usually made of thicker wire than the primary. Explain why.
An a.c generator generates an emf 'ε' where ε = 314 Sin (50πt) volt. Calculate the frequency of emf ε.
State the factors on which the frequency of the alternating e.m.f. depends.
Transformer works on ______.
A step-down transformer connected to the main supply of 220 V is used to operate 11V,88W lamp. Calculate
- Voltage transformation ratio and
- Current in the primary
A 100% efficient transformer has 100 turns in the primary and 50 turns in its secondary coil. If the current in the secondary coil is 6 A, then the current in the primary coil 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.
If the secondary coil has a greater number of turns than the primary, ______.
A transformer is used ______
Two coils P and Q are kept near each other. When no current flows through coil P and current increase in coil Q at the rate 10A/s, the emf in coil P is 15mV. When coil Q carries no current and current of 1. 8A flows through coil P, the magnetic flux linked with the coil Q is ______.
