Advertisements
Advertisements
Question
Describe briefly and two energy losses, giving the reasons for their occurrence in actual transformers ?
Advertisements
Solution
Energy losses occur in transformers:
(i) Flux leakage: Not all of the flux due to primary coil passes through the secondary due to poor design of the core or the air gaps in the core.
(ii) Eddy currents: The alternating magnetic flux induces eddy currents in the iron core and causes heating.
RELATED QUESTIONS
Explain the construction and working of the transformer.
Derive an expression for ratio of e.m.f.s and currents in terms of number of turns in primary and secondary coil.
The primary coil of an ideal step-up transformer has 100 turns and the transformation ratio is also 100. The input voltage and power are 220 V and 1100 W, respectively. Calculate the
(a) number of turns in secondary
(b) current in the primary
(c) a voltage across secondary
(d) current in secondary
(e) power in secondary
State the principle of working of a transformer. Can a transformer be used to step up or step down a d.c. voltage? Justify your answer.
Copy the given diagram of a transformer and complete it. Name the parts A and B. Name the part you have drawn to complete the diagram. What is the material of this part? Is this transformer a step-up or step-down? Give reason.
Distinguish between Step up and Step Down Transformer.
In a series resonant RLC circuit, the voltage across 100 Ω resistor is 40 V. The resonant frequency ω is 250 rad/s. If the value of C is 4 µF, then the voltage across L is
A transformer having efficiency of 80% is working on 200 V and 6 kW power supply. If the current in the secondary coil is 6 A, the voltage across the secondary coil and the current in the primary coil respectively are ____________.
A step down transformer connected to an AC mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?
An ideal transformer converts 170 V a.c. to 1.70 KV a.c. to transmit a power of 3.4 KW. If primary coil has 500 turns then alternating current in secondary coil is ______.
