Advertisements
Advertisements
प्रश्न
Draw the effective equivalent circuit of the circuit shown in figure, at very high frequencies and find the effective impedance.
Advertisements
उत्तर
The element with infinite resistance will be considered as open circuit and the element with zero resistance will be considered as short-circuited.
In similar way, `X_C = 1/(2pivC)`
At high frequency, XC will be low.
So reactance of capacitance can be considered negligible and capacitor can be considered as short-circuited.
Here the above figure is equivalent circuit to given circuit.
Total impedance,Z = R1 + R3
APPEARS IN
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.
A group of students while coming from the school noticed a box marked "Danger H.T. 2200 V" at a substation in the main street. They did not understand the utility of a such a high voltage, while they argued, the supply was only 220 V. They asked their teacher this question the next day. The teacher thought it to be an important question and therefore explained to the whole class.
Answer the following questions:
(i) What device is used to bring the high voltage down to low voltage of a.c. current and what is the principle of its working ?
(ii) Is it possible to use this device for bringing down the high dc voltage to the low voltage? Explain
(iii) Write the values displayed by the students and the teacher.
Mention various energy losses in transformer device
Why is the core of a transformer laminated?
State the underlying principle of a transformer. How is the large scale transmission of electric energy over long distances done with the use of transformers?
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.
Draw a labeled diagram of a full wave rectifier circuit. State its working principle. Show the input-output waveforms ?
State the factors on which the frequency of the alternating e.m.f. depends.
Name the principle on which functioning of a transformer depends.
Applying e.m. f to primary coil is 210 V. If the number of turns in primary coil is 200 turns and that of in secondary coil is 20 turns, then find out the output voltage. Name the type of transformer.
A transformer lowers e.m.f. from 220 V to 15 V. If 400 W power is given in primary, calculate (i) the current in primary coil and (ii) the current in secondary coil.
Transformer works on ______.
Assertion: A transfonner cannot work on D.C. supply.
Reason: D.C. changes neither in magnitude nor in direction.
The primary winding of a transformer has 100 turns and its secondary winding has 200 turns. The primary is connected to an a.c supply of 120 V and the current flowing in its is 10 A. The voltage and the current in the secondary are ______.
The primary coil having NP turns of an ideal transformer is supplied with an alternating voltage VP. Obtain an expression for the voltage VS induced in its secondary coil having NS turns.
The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.
If a current of 5A flows in the primary coil, how much current will flow in a load in the secondary coil? State the assumption you have made regarding the transformer, in this calculation.
What type of transformer is used in a mobile phone charger?
Explain why core of a transformer is always laminated.
