In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are?
Last Answer : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are hysteresis and eddy current losses.
Show More
152 views
1 answer
asked
Mar 19, 2018
by
anonymous

State any four characteristics of core type transformer.
Last Answer : Characteristics of core type transformer: i) It has one window. ii) It has one magnetic circuit. iii) Core surrounds the winding. iv) Average length of core is more. v) Area of cross ... Better cooling for winding. vii) Mechnical strength is comparatively less. viii) Repair and maintenance is easy.
Show More
132 views
1 answer
asked
Jul 27, 2019
by
anonymous

Last Answer : Material used for construction of transformer core is usually silicon steel.
Show More
241 views
1 answer
asked
Mar 19, 2018
by
anonymous

When secondary of a current transformer is open-circuited its iron core will be?
Last Answer : When secondary of a current transformer is open-circuited its iron core will be hot because of heavy iron losses taking place in it due to high flux density.
Show More
165 views
1 answer
asked
Mar 19, 2018
by
anonymous

The size of a transformer core will depend on?
Last Answer : The size of a transformer core will depend on frequency and area of the core.
Show More
114 views
1 answer
asked
Mar 19, 2018
by
anonymous

Explain the electrical losses of magnetic materials used for the cores of inductors and transformer.
Show More
87 views
0 answers
asked
Mar 10, 2018
by
anonymous

A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is
Last Answer : A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is 0.707
Show More
774 views
1 answer
asked
May 8, 2018
by
anonymous

The core construction is like spokes of a wheel in following transformer: (A) Berry Type Transformer (B) Core Type Transformer (C) Shell Type Transformer (D) None of the above
Last Answer : The core construction is like spokes of a wheel in following transformer: Berry Type Transformer
Show More
133 views
1 answer
asked
May 8, 2018
by
anonymous
.jpg)
The desirable properties of transformer core material are (1) low permeability and low hysteresis loss. (2) high permeability and high hysteresis loss. (3) high permeability and low hysteresis loss. (4) low permeability and hysteresis loss.
Last Answer : The desirable properties of transformer core material are high permeability and low hysteresis loss.
Show More
229 views
1 answer
asked
May 1, 2018
by
anonymous

The main purpose of using core in a transformer is to (A) decrease iron losses (B) eliminate magnetic hysteresis (C) reduce reluctance of the common magnetic circuit (D) prevent eddy current loss
Last Answer : Reduce Relucatnce of the common magnetic circuit.
Show More
2.0k views
2 answers
asked
Apr 28, 2018
by
anonymous

Why does the core of a transformer need to be laminated?
Last Answer : Transformer cores are laminated to reduce eddy current loss.
Show More
122 views
1 answer
asked
Mar 14, 2018
by
anonymous

Last Answer : Transformer core is laminated to reduce Eddy current losses.
Show More
112 views
1 answer
asked
Sep 30, 2017
by
anonymous

Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is?
Last Answer : Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is approximately equal to 1.
Show More
160 views
1 answer
asked
Mar 19, 2018
by
anonymous
.jpg)
(a) Define permeability. (b) Define MMF. (c) Define form factor of an alternating quantity. (d) Define frequency and time period of an alternating quality. (e) Define transformation ratio of transformer. ... and state the meaning of each term used. (g) Give two applications of single phase motors.
Last Answer : Permeability : It is the ability of a magnetic/Non magnetic material to allow setting up of flux in it. MMF : The magneto motive force (MMF) is the force required to setup flux in a magnetic / ... applications of single phase motors : Water pumps, ceiling fan, lathe machine
Show More
210 views
1 answer
asked
Aug 21, 2019
by
anonymous

Losses which occur in rotating electric machines and do not occur in transformers are?
Last Answer : Friction losses windage losses
Show More
208 views
2 answers
asked
Mar 19, 2018
by
anonymous

For given applied voltage, with the increase in frequency of the applied voltage?
Last Answer : For given applied voltage, with the increase in frequency of the applied voltage eddy current loss will remain unchanged.
Show More
238 views
1 answer
asked
Mar 19, 2018
by
anonymous

13) In an ideal transformer A. windings have no resistance B. core has no losses C. core has infinite permeability D. all of the above
Last Answer : D. All of the above
Show More
42 views
1 answer

n an ideal transformer A. windings have no resistance B. core has no losses C. core has infinite permeability D. all of the above
Show More
4 views
0 answers

Purpose of Selective Catalytic Reduction (SCR)
Last Answer : Purpose of Selective Catalytic Reduction (SCR) : 1. It reduces Nox 75% to 90% 2. Converts it in to molecular nitrogen and water vapor 3. It reduces HC emission up to 80% 4. It reduces PM emission 20 to 25%.
Show More
26 views
1 answer
asked
Jan 2, 2021
by
anonymous

Last Answer : When a bogie negotiates a curve, reduction in adhesion occurs resulting in sliding. Thus sliding is acute when wheel base of axles is more, degree of curvature is more.
Show More
196 views
1 answer
asked
Mar 22, 2018
by
anonymous

State the need for reduction of harmonics in inverters. Enlist the various methods for reduction of harmonics in inverter output.
Show More
55 views
0 answers
asked
Mar 10, 2018
by
anonymous

Define magnetic permeability. State and explain the factors affecting permeability of magnetic materials
Last Answer : Permeability : The capability of the magnetic material to conduct the magnetic flux is known as permeability. Permeability and hysteresis loss are inversely related to each other. Factors ... impurities affect the geometric pattern of the crystals and are harmful to the magnetic property.
Show More
213 views
1 answer
asked
Aug 5, 2019
by
anonymous
.jpg)
Permeability formula
Last Answer : Permeability formula
Show More
54 views
1 answer
asked
Jun 11, 2019
by
anonymous
.jpg)
Give the relation between magnetic field strength, magnetic flux density and permeability.
Show More
84 views
0 answers
asked
Aug 8, 2018
by
anonymous

State the values of permeability of free space and relative permeability of air.
Show More
177 views
0 answers
asked
Aug 8, 2018
by
anonymous

Define permeability.
Last Answer : Permeability is the ability with which the magnetic material forces the magnetic flux through a given medium. Permeability is the magnetic property of the medium. The flow of flux in a magnetic ... field strength (H) is same for both. Relative permeability is unitless it has no dimensions.
Show More
97 views
1 answer
asked
Aug 8, 2018
by
anonymous

The magnetic permeability of a diamagnet is _________ A) More than that of vacuum B) Same as that of vacuum C) Less than that of vacuum D) 3.14 times that of vacuum
Last Answer : The magnetic permeability of a diamagnet is Less than that of vacuum
Show More
86 views
1 answer
asked
Apr 29, 2018
by
anonymous

Relative permeability of vacuum is?
Last Answer : Relative permeability of vacuum is 1.
Show More
78 views
1 answer
asked
Mar 25, 2018
by
anonymous

Permeability in a magnetic circuit corresponds to______ in an electric circuit.
Last Answer : Permeability in a magnetic circuit corresponds to conductivity in an electric circuit.
Show More
592 views
1 answer
asked
Mar 25, 2018
by
anonymous

The relative permeability of a ferromagnetic material is?
Last Answer : The relative permeability of a ferromagnetic material is more than 100 or 1000.
Show More
104 views
1 answer
asked
Mar 25, 2018
by
anonymous

State the losses in secondary distribution system.
Last Answer : The losses in secondary distribution system: a) Technical losses: 1. Due to poor voltage 2. Due to unbalance load 3. Due poor quality of transformer & its components 4. Due to poor quality ... of induction type of energy meter. 3. Lack of administration. 4. Energy theft 5. Unmetered supply
Show More
122 views
1 answer
asked
May 3, 2020
by
anonymous

Explain the “mitigation of power theft” and “faulty meter replacement” for energy conservation techniques to reduce commercial losses.
Last Answer : Energy conservation techniques to reduce commercial losses: 1. Mitigation of Power Theft: Power theft being the most important issue which all of the service providing utilities ... agricultural sector. Prepaid meters may prove effective measures against unauthorized abstraction of energy.
Show More
120 views
1 answer
asked
Sep 22, 2018
by
anonymous

Explain following techniques related to energy conservation in transmission and distribution system. (i) By balancing phase currents (ii) Variable technical losses (I2R losses).
Last Answer : (i) Balancing Phase currents: Proper (healthy balanced) three phase loads always draw equal currents in all lines but single phase loads in the 3 phase 4 wire system or loads connected between two ... . 11) Minimize I2R losses. 12) Balance the load currents. 13) Regulate the system voltages.
Show More
194 views
1 answer
asked
Sep 22, 2018
by
anonymous

The friction losses in Real Transformers are : (A) 0% (B) 5% (C) 25% (D) 50%
Last Answer : A
Show More
3.3k views
2 answers
asked
May 8, 2018
by
anonymous

Which of the following can reduce the Eddy current losses? A) By making the core of a stack of plates electrically insulated from each other B) By making the core of solid block C) By increasing the applied voltage D) None of these
Last Answer : Which of the following can reduce the Eddy current losses? A) By making the core of a stack of plates electrically insulated from each other B) By making the core of solid block C) By increasing the applied voltage D) None of these
Show More
90 views
1 answer
asked
Apr 29, 2018
by
anonymous

In DC motor iron losses are occurred in?
Last Answer : In DC motor iron losses are occurred in the armature.
Show More
138 views
1 answer
asked
Mar 26, 2018
by
anonymous

Last Answer : Iron losses in a D.C. machine are independent of variations in load.
Show More
161 views
1 answer
asked
Mar 20, 2018
by
anonymous
.jpg)
Last Answer : In case of D.C. machines, mechanical losses are primary function of speed.
Show More
499 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a D.C. generator, the iron losses mainly take place in armature rotor.
Show More
273 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The total losses in a well designed D.C. generator of 10 kW will be nearly 500 W.
Show More
138 views
1 answer
asked
Mar 20, 2018
by
anonymous

In a synchronous motor which losses varies with load?
Last Answer : In a synchronous motor, copper losses varies with load.
Show More
102 views
1 answer
asked
Mar 18, 2018
by
anonymous

What are the losses in a transmission line?
Show More
61 views
0 answers
asked
Mar 10, 2018
by
anonymous

What are the types of power losses in inductor?
Last Answer : Copper losses, Eddy current loss, and hysteresis loss are the types of power losses in inductor.
Show More
118 views
1 answer
asked
Mar 8, 2018
by
anonymous

What is the percentage of stray losses in DC machine?
Last Answer : Percentage of stray losses in DC machine is about 1 % .
Show More
115 views
1 answer
asked
Mar 8, 2018
by
anonymous

In synchronous motor, does the winding losses vary with load?
Last Answer : No, in the synchronous motor the winding losses do not vary with load.
Show More
512 views
1 answer
asked
Mar 3, 2018
by
anonymous

Last Answer : Iron loss, copper loss and mechanical losses these are the losses in DC machine.
Show More
118 views
1 answer
asked
Sep 27, 2017
by
anonymous

Explain the on state losses in power BJT.
Last Answer : On state losses in power BJT: Transistor have four types of losses one is turn on state losses second is turn off state losses third is turn on switching losses and fourth is turn ... ON = VCE sat x IC With increasing collector current collector to emitter saturation voltage increases.
Show More
295 views
1 answer
asked
Sep 15, 2017
by
anonymous

Last Answer : The purpose of providing an iron core in a transformer is to decrease the reluctance of the magnetic path.
Show More
202 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : The purpose of providing iron core in a step-up transformer is to decrease the magnitude of magnetizing current.
Show More
545 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : The core used in high frequency transformer is usually air core .
Show More
213 views
1 answer
asked
Mar 19, 2018
by
anonymous
