Advertisements
Advertisements
Question
Can a transformer be used with direct current source? Give reason.
Advertisements
Solution
No, a transformer cannot be used with direct current source. The reason is that with direct current source, there will not be any change in the magnetic flux linked with the primary coil, so no e.m.f. will be induced in the secondary coil.
RELATED QUESTIONS
Derive an expression for ratio of e.m.f.s and currents in terms of number of turns in primary and secondary coil.
Derive an expression for e.m.f. and current in terms of turns ratio
What is the function of a transformer in an a.c. circuit? How do the input and output powers in a transformer compare?
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?
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.
We need to step-up the voltage for power transmission, so that ______.
Draw the effective equivalent circuit of the circuit shown in figure, at very high frequencies and find the effective impedance.
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 ______.
An ideal transformer converts 220 V a.c. to 3.3 kV a.c. to transmit a power of 4.4 kW. If primary coil has 600 turns, then alternating current in secondary coil is ______.
For what purpose are the transformers used?
