Advertisements
Advertisements
Question
Distinguish between Step up and Step Down Transformer.
Advertisements
Solution
| No. | Step-up transformer | Step-down transformer |
| i. | The number of turns in its secondary is more than that in its primary (NS > NP). | The number of turns in primary is greater than in secondary (NP > NS). |
| ii. | The alternating voltage across the ends of its secondary is more than that across its primary, i.e., eS > eP. | The alternating voltage across the ends of the primary is more than that across its secondary, i.e., eP > eS. |
| iii. | Transformer ratio K > 1. | Transformer ratio K < 1. |
| iv. | Primary coil made of thick wire. | Secondary coil made of thick wire. |
| v. | The secondary coil is made of thin wire. | The primary coil is made of thin wire. |
| vi. | Current through secondary is less than primary. | Current through primary is less than secondary. |
RELATED QUESTIONS
Write the function of a transformer.
State the principle of the step-down transformer and its working.
State the principle of transformer working with the help of a diagram
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
Which coil of a step up transformer is made thicker and why?
On which type of current do transformers work?
Explain the significance of Lenz’s law to show the conservation of energy in electromagnetic induction.
For what purpose are the transformers used? Can they be used with a direct current source?
What is the function of a transformer in an a.c. circuit? How do the input and output powers in a transformer compare?
Name two kind of energy loss in a transformer. How is it minimized?
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?
Given the input current 15 A and the input voltage of 100 V for a step-up transformer having 90% efficiency, find the output power and the voltage in the secondary if the output current is 3 A.
Mention the two characteristic properties of the material suitable for making core of a transformer.
Describe briefly and two energy losses, giving the reasons for their occurrence in actual 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.
Describe briefly, with the help of labelled diagram, working of a step-up transformer.
A step-up transformer converts a low voltage into high voltage. Does it not violate the principle of conservation of energy? Explain.
An a.c generator generates an emf 'ε' where ε = 314 Sin (50πt) volt. Calculate the frequency of emf ε.
State the principle of a transformer.
Name the principle on which functioning of a transformer depends.
A transformer lowers e.m.f. 220 V to 12 volts. If the number of turns in primary are 8800, how many turns are in secondary 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?
The primary and secondary coils of a transformer each have an inductance of 200 x 10-6 H. The mutual inductance between the windings is 4 x 10-6 H. What percentage of the flux from one coil reaches the other?
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 ______.
What is Transformer?
Explain step up and step down transformer?
Devices which is used to convert high alternating current to low alternating current is ______.
What are step-up and step-down transformers?
Explain the construction of transformer.
Explain the working of the transformer.
Find out the phase relationship between voltage and current in a pure inductive circuit.
The 300 turn primary of a transformer has resistance 0.82 Ω and the resistance of its secondary of 1200 turns is 6.2 Ω. Find the voltage across the primary if the power output from the secondary at 1600V is 32 kW. Calculate the power losses in both coils when the transformer efficiency is 80%
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.
Which of the following statement is true?
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, ______.
The primary coil of a transformer has 800 turns and the secondary coil has 8 turns. It is connected to a 220 V ac supply. What will be the output voltage?
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?
For an LCR circuit, the power transferred from the driving source to the driven oscillator is P = I2Z cos φ.
- Here, the power factor cos φ ≥ 0, P ≥ 0.
- The driving force can give no energy to the oscillator (P = 0) in some cases.
- The driving force cannot syphon out (P < 0) the energy out of oscillator.
- The driving force can take away energy out of the oscillator.
The line that draws power supply to your house from street has ______.
- zero average current.
- 220 V average voltage.
- voltage and current out of phase by 90°.
- voltage and current possibly differing in phase `phi` such that `|phi| < pi/2`.
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 ______.
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 ______.
An iron rod of 0.2 cm2 cross-sectional area is subjected to a magnetising field of 1200 Am-1. If the susceptibility of iron is 599, then the magnetic flux produced is ______.
Mention two main sources of power loss in real transformers.
The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.
If a 220 V ac voltage is applied to the primary coil, how much emf is induced in the secondary coil?
What is a transformer?
For what purpose are the transformers used?
How do the input and output powers in a transformer compare? State the assumption made.
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?
