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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
Draw a labeled diagram of a step-down transformer.
How is the e.m.f. across primary and secondary coils of a transformer related with the number of turns of the coil in them?
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?
Can a transformer be used with direct current source? Give reason.
The power supply to the primary coil of a transformer is 200 W. Find
(i) Current in primary coil if the e.m.f. supply to it is equal to 220V.
(ii) The number of turns in the primary coil is equal to 80 and that in secondary is 800. What is the transformation ratio?
(iii) Name the type of transformer.
(iv) What will be the output voltage?
(v) What is the current in the secondary coil for an ideal transformer?
(vi) What is the output power?
(vii) Is output and input power equal?
(viii) Compare the current flowing in a secondary coil and in a primary coil.
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?
A circular coil of 100 turns with a cross-sectional area of 1 m2 is kept with its plane perpendicular to the magnetic field of 1 T. The magnetic flux linkage is ______.
The primary of a transformer has 40 turns and works on 100 V and 100 W. Find a number of turns in the secondary to step up the voltage to 400 V. Also calculate the current in the secondary and primary.
The magnetic flux through a coil perpendicular to its plane is varying according to the relation Φ = (5t3 + 4t2 + 2t - 5) Weber. If the resistant of the coil is 5 ohm, then the induced current through the coil at t = 2 sec will be ______.
How do the input and output powers in a transformer compare? State the assumption made.
