Description : The magnetic susceptibility of paramagnetic material is: A) Less than zero B) Less than one but positive C) Greater than one D) Equal to zero
Answer :
The magnetic susceptibility of paramagnetic material is: Less than one but positive
asked
Jun 18, 2018
by
anonymous
Description : Define magnetic lines of force. Also draw and show magnetic lines of force of a bar type magnet.
Answer :
Magnetic Lines of force- These are the imaginary lines (having no physical existence) introduced by Faraday for the pictorial representation of the distribution of a magnetic field. OR A line of ... that the tangent at any point gives direction of the resultant force at that point.
asked
Sep 4, 2018
by
anonymous
Description : What is the value of susceptibility in case of vacuum? A) 1 B) 0.5 C) ∞ D) 0
Answer :
What is the value of susceptibility in case of vacuum? A) 1 B) 0.5 C) ∞ D) 0
asked
Jun 18, 2018
by
anonymous
Answer :
Susceptibility of the air medium is zero.
asked
Mar 26, 2018
by
anonymous
Description : Define polarization.
asked
Mar 11, 2018
by
anonymous
Description : Define magnetic permeability. State and explain the factors affecting permeability of magnetic materials
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.
asked
Aug 5, 2019
by
anonymous
Description : Define the following terms: i) Magnetic flux density, ii) Reluctance, iii) Magneto-motive force, iv) Permeance.
Answer :
(i) Magnetic flux density (B): It is the magnetic flux per unit area measured at right angles to the flux path. (Its unit is weber/m2 or tesla). (ii) Reluctance: It is the ... flux to set up through it and it is reciprocal of reluctance. Permeance = 1/ Reluctance. Unit: weber/ampere.
asked
Sep 4, 2018
by
anonymous
Description : Define magnetic circuit. Draw simple series magnetic circuit.
asked
Aug 8, 2018
by
anonymous
Description : Define magnetic flux density and state its formula.
Answer :
The magnetic flux per unit area is called as magnetic flux density. Magnetic flux density is denoted by B. The formula for magnetic flux density is Weber per metre square or Tesla. Mathematically ... the unit of magnetic flux density is Weber per metre square which is also called as Tesla.
asked
Aug 8, 2018
by
anonymous
Description : Define magnetic field strength and state its unit.
Answer :
Magnetic field strength is the force experienced by a unit N-pole when placed at any point in a magnetic field is known as magnetic field strength or magnetizing force. Magnetising force or magnetic field ... unit of length is metre. So the unit of magnetic field strength is ampere turns per metre.
asked
Aug 8, 2018
by
anonymous
Description : Define magnetic lines of force. Show the magnetic lines of force for bar type magnet.
Answer :
Magnetic linens of force is the imaginary lines for magnetic field of magnet around it. These magnetic lines of forces are introduced by Michael Faraday. The direction of lines of force is from N-pole to S-pole. The figure shows lines of force for bar type magnet.
asked
Aug 8, 2018
by
anonymous
Description : Magnetic and Non-magnetic Materials
Answer :
We have now looked at a number of ways in which matter can be grouped, such as into metals, semi-metals and non-metals; electrical conductors and insulators, and thermal conductors and insulators. ... information must be stored, in computers and TV's, as well as in generators and electric motors.
Description : Why does the magnetic field flow from north to south?
asked
May 27, 2020
by
anonymous
Description : State the material used for making (1) Magnetic Core (2) Fuse element
Answer :
The material used for making of: (1) Magnetic Core : Iron, cobalt, Nickel, CRGO, HRGO , silicon steel (2) Fuse Element: Tin- lead wire, Tinned copper wire
asked
May 7, 2020
by
anonymous
Description : Electro Magnetic Induction
Answer :
Electro Magnetic Induction
asked
May 5, 2020
by
anonymous
Description : Why does leakage occur in a magnetic circuit?
asked
May 5, 2020
by
anonymous
Description : Why is it necessary to keep air gaps in magnetic circuits as small as possible?
asked
May 5, 2020
by
anonymous
Description : Explain with neat diagram series and parallel magnetic circuits.
Answer :
Series magnetic circuit: When different magnetic materials having different lengths, cross sectional areas and permeability are connected one after another, in which same flux is established in different sections, then it is called series ... flux, Φ = Φ1 + Φ2 Path 1: BAFE Path 2: BACD
asked
Apr 27, 2020
by
anonymous
Description : Series Magnetic Circuits
asked
Apr 26, 2020
by
anonymous
Description : Important Terms in Magnetic Circuit
Answer :
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asked
Apr 24, 2020
by
anonymous
Description : Magnetic Circuit and its Analysis
Answer :
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asked
Apr 24, 2020
by
anonymous
Description : A magnetic circuit has effective iron length of 100 cm and it is wound with 800 turns of wire carries 1 A. Find the magnetic field strength.
Answer :
magnetic field strength
asked
Mar 30, 2020
by
anonymous
Description : What arc the errors occurring in measuring devices due to stray magnetic field and temp '? Explain how to compensate them.
Answer :
1. Error due to stray magnetic fields- Main magnetic field gets disturbed by external magnetic fields known as stray magnetic fields. 2. Compensation technique To avoid this error, ... resistance alloy having a negligible resistance temp coefficient in the ratio of 1:10 for pressure coil
asked
Sep 6, 2018
by
anonymous
Description : Explain magnetic effect employed in measuring instrument.
Answer :
Magnetic Effect: I) In PMMC meters: ➢ When a current is passed through a conductor, magnetic field is produced round the conductor. Due to this field when current ... field it experiences a mechanical force. Examples: Electrodynamometer type instruments, Induction type instrument.
asked
Sep 6, 2018
by
anonymous
Description : Derive an expression for energy stored in a magnetic field .
Answer :
Expression for energy stored in a magnetic field: The energy is stored in magnetic field when current increases and return back when the current decreases. At instant t' seconds after closer of switch ... energy absorbed by the magnetic field when current increases from 0 to I amperes
asked
Sep 4, 2018
by
anonymous
Description : What is magnetic hysteresis? What is the cause of hysteresis?
Answer :
Magnetic hysteresis: When a magnetic material is subjected to cycle of magnetization, it is found that flux density (B) in the material lags behind applied magnetizing force (H). This ... the movement of orientation, due to which the flux density lags behind the magnetic field intensity.
asked
Sep 4, 2018
by
anonymous
Description : Classify magnetic materials and explain in brief.
Answer :
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asked
Sep 4, 2018
by
anonymous
Description : State and explain Ohm's law for magnetic circuit.
Answer :
Ohm's law for electric circuit is V = I R where V is voltage, I is current, R is Resistance. Ohm's law for magnetic circuit is MMF = Φ X S where MMF is magnetomotive force (NI) ... . Resistance is the opposition to the flow of current while reluctance is the opposition to the flow of magnetic flux.
asked
Aug 10, 2018
by
anonymous
Description : Compare electric and magnetic circuit.
Answer :
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asked
Aug 8, 2018
by
anonymous
Description : Give the relation between magnetic field strength, magnetic flux density and permeability.
asked
Aug 8, 2018
by
anonymous
Description : Magnetic circuit breakers use _________ A) Permanent magnets B) Earth magnets C) Solenoid D) All the above
Answer :
Magnetic circuit breakers use Solenoid
asked
Apr 29, 2018
by
anonymous
Description : Which of the following is a unit of magnetic flux? A) Weber B) Maxwell C) Both A and B D) None of these
Answer :
Which of the following is a unit of magnetic flux? A) Weber B) Maxwell C) Both A and B D) None of these
asked
Apr 29, 2018
by
anonymous
Description : What is the SI unit for magnetic reluctance? A) Ampere B) Ampere-turns per weber C) Henry D) None of these
Answer :
What is the SI unit for magnetic reluctance? A) Ampere B) Ampere-turns per weber C) Henry D) None of these
asked
Apr 29, 2018
by
anonymous
Description : Which of the following laws relates the magnetic field to the magnitude, direction, length, and proximity of the electric current? A) Lenz’s law B) Faraday’s law C) Biot–Savart law D) None of these
Answer :
Which of the following laws relates the magnetic field to the magnitude, direction, length, and proximity of the electric current? A) Lenz’s law B) Faraday’s law C) Biot–Savart law D) None of these
asked
Apr 29, 2018
by
anonymous
Description : 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
Answer :
The magnetic permeability of a diamagnet is Less than that of vacuum
asked
Apr 29, 2018
by
anonymous
Description : The magnetic neutral plane shifts in a dc machine (A) in the direction of motion of motor (B) in the direction of motion of generator (C) due to increase in the field flux (D) cause reduction of flash over between commutator segments
Answer :
The magnetic neutral plane shifts in a dc machine in the direction of motion of generator
asked
Apr 28, 2018
by
anonymous
Description : Which of the following statements is not characteristic of a static magnetic field? (A) It is solenoidal. (B) It is conservative. (C) It has no sinks or sources. (D) Flux lines are always closed.
Answer :
Which of the following statements is not characteristic of a static magnetic field? (A) It is solenoidal. (B) It is conservative. (C) It has no sinks or sources. (D) Flux lines are always closed.
asked
Apr 28, 2018
by
anonymous
Description : The property of a material which opposes the creation of magnetic flux in it is known as?
Answer :
The property of a material which opposes the creation of magnetic flux in it is known as reluctance.
asked
Mar 25, 2018
by
anonymous
Description : In a magnetic material hysteresis loss takes place primarily due to?
Answer :
In a magnetic material hysteresis loss takes place primarily due to it high retentivity.
asked
Mar 25, 2018
by
anonymous
Description : A material for good magnetic memory should have?
Answer :
A material for good magnetic memory should have high retentivity.
asked
Mar 25, 2018
by
anonymous
Description : Those magnetic materials are best suited for making armature and transformer cores which have____permeability and_______hystersis loss.
Answer :
Those magnetic materials are best suited for making armature and transformer cores which have high permeability and low hystersis loss.
asked
Mar 25, 2018
by
anonymous
Description : Permeability in a magnetic circuit corresponds to______ in an electric circuit.
Answer :
Permeability in a magnetic circuit corresponds to conductivity in an electric circuit.
asked
Mar 25, 2018
by
anonymous
Description : The unit of magnetic flux is?
Answer :
The unit of magnetic flux is weber.
asked
Mar 25, 2018
by
anonymous
Description : An air gap is usually inserted in magnetic circuits to?
Answer :
An air gap is usually inserted in magnetic circuits to prevent saturation.
asked
Mar 25, 2018
by
anonymous
Answer :
To avoid the effect of stray magnetic field in A.C. bridges we can use magnetic screening.
asked
Mar 21, 2018
by
anonymous
Answer :
In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis, when there is no load on|he generator.
asked
Mar 21, 2018
by
anonymous
Answer :
Magnetic field in a D.C. generator is produced by electromagnets.
asked
Mar 20, 2018
by
anonymous
Answer :
As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for sound equipment.
asked
Mar 20, 2018
by
anonymous
Answer :
The voltage regulation in magnetic amplifier type voltage regulator is effected by varying the reactance.
asked
Mar 20, 2018
by
anonymous
Answer :
Magnetic circuit breaker has instantaneous trip action.
asked
Mar 19, 2018
by
anonymous