What do you mean by electromagnetic field?

Related Questions

Description : What are the electromagnetic waves used in remote control?

Description : What are the dangers of electromagnetic waves?

Description : What is the speed of an electromagnetic wave in water?

Description : How fast is an electromagnetic wave?

Description : What is an example of an electromagnetic?

Description : What is the definition of electromagnetic force?

Description : How can a magnetic field be used to generate an electric current?

Last Answer : Magnetic  field  can  be  used  to  generate  electric  current  on  a  condition  that  it  is  on  a  rate  of  changing  magnetic  flux.  (Faraday's  law)

Description : Define Faraday’s first law of electromagnetic induction. 

Last Answer : Faraday’s First Law: Whenever a changing magnetic flux links with a conductor, an emf is induced in that conductor.  OR  When a conductor cuts across magnetic field, an emf is induced in that conductor.

Description : State advantages & disadvantages of electromagnetic flow meter.

Last Answer : Advantage: Provides wide linear range. 2) Ability to measure reverses flow. 3) Gives rapid response to flow changes. 4) No obstruction is created to flow. 5) It can handle corrosive as ... and pipe networks with relatively short inside diameters. 3) It is useful for electrically conducting fluid.

Description : i) Explain electromagnetic spectrum with neat diagram. ii) Explain atmospheric noise with example. 

Last Answer : Explanation:-  The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths  The electromagnetic spectrum covers ... spread over the complete frequency spectrum used for radio communication.  Example: Lightning 

Description : Justify electromagnetic wave is said to be transverse wave. 

Last Answer : Transverse electromagnetic wave:- The electromagnetic waves are oscillations which propagate through free space. In electromagnetic waves the direction of electric field, magnetic field & propagation are ... electric field vector with respect to the surface (i.e. looking at the horizon) 

Description : State Faraday's law of electromagnetic induction.

Last Answer : First Law: - Whenever change in the magnetic flux linked with a coil or conductor, an EMF is induced in it. OR Whenever a conductor cuts magnetic flux, an EMF is induced in conductor.  Second Law: ... of induced EMF is directly proportional to (equal to) the rate of change of flux linkages.

Description : What is the frequency range of VHF electromagnetic waves? A) 30-300 kHz B) 30-3000 kHz C) 30-300 MHz D) 30-3000 MHz

Last Answer : What is the frequency range of VHF electromagnetic waves? A) 30-300 kHz B) 30-3000 kHz C) 30-300 MHz D) 30-3000 MHz

Last Answer : Magnetic field in a D.C. generator is produced by electromagnets.

Last Answer : In a shaded pole single-phase motor, the revolving field is produced by the use of shading coils.

Description : How to Kick a Football Field Goal

Last Answer : How to Kick a Football Field Goal There are only a few seconds left in the game, and one field goal attempt is all that stands between you and gridiron glory, or a place in the Hall of Shame. ... right kick for the right play, and get that game-winning field goal just right between the goal posts.

Description : How to Plow a Field

Last Answer : How to Plow a Field Civilization began when human beings started to turn over the soil to plant food. Plowing may have come a long way since the first human beings used their hands and ... budget. With these tools, you can plow fields and help contribute to the advancement of human civilization.

Description : How to Field Dress a Deer ?

Last Answer : How to Field Dress a Deer If you enjoy hunting deer, there's one important task you need to do before you can haul your prized catch back home: you'll need to field dress it. Field dressing ... you go hunting. Just follow these steps and you'll bring your prized catch home without any trouble.

Description : Why does the magnetic field flow from north to south?

Description : State advantages of rotating field type alternators. 

Last Answer : Advantages of Rotating Field Type Alternator: 1) For high-voltage alternator, large space is required to accommodate conductors with insulation, as high voltage is induced in them. If field poles are placed ... is kept rotating. 8) Rotating field is comparatively light and can run with high speed. 

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.

Last Answer : magnetic field strength

Description : Briefly describe the electric field of a static charge.

Description :  Field intensity formula

Last Answer :  Field intensity formula

Description : Energy stored in electrostatic field of capacitance formula

Last Answer : Energy stored in electrostatic field of capacitance formula

Description : What arc the errors occurring in measuring devices due to stray magnetic field and temp '? Explain how to compensate them.

Last 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 

Description : Define junction field effect transistor (JFET) and give an example.

Last Answer : Junction Field-Effect Transistor: It is a semiconductor device having three terminals, namely Gate, Drain and Source, in which the current flow is controlled by an electric field set up by an external voltage applied ... : i) n-channel JFET and ii) p-channel JFET Examples of JFET: BFW 10, BFW 11 

Description : Derive an expression for energy stored in a magnetic field . 

Last 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 

Description : Give the relation between magnetic field strength, magnetic flux density and permeability.

Description : Define magnetic field strength and state its unit.

Last 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.

Description : In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as  (1) synchronous motor (2) synchronous generator (3) asynchronous motor (4) asynchronous generator

Last Answer : In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as synchronous generator 

Description : The ability of materials to become polarized under an applied electric field is called _______ A) Ferroelectricity B) Paraelectricity C) Polectricity D) None of these

Last Answer : The ability of materials to become polarized under an applied electric field is called Paraelectricity

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

Last 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

Description : The electric field inside a hollow conducting sphere ________ A) Depends on the diameter of the sphere  B) Varies according to the direction of earth’s magnetic poles C) Is zero  D) None of these

Last Answer : The electric field inside a hollow conducting sphere Is zero

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.

Last 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.

Description : It is possible to increase the field flux and, at the same time, increase the speed of a d.c. motor provided its .......... is held constant.

Last Answer : It is possible to increase the field flux and, at the same time, increase the speed of a d.c. motor provided its armature current is held constant.

Description : A field of force can exist only between?

Last Answer : A field of force can exist only between two ions.

Last Answer : To avoid the effect of stray magnetic field in A.C. bridges we can use magnetic screening.

Description : A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave?

Last Answer : A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave will be of 5 Hz.

Last Answer : Flashing the field of D.C. generator means creating residual magnetism by a D.C. source.

Last Answer : If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens this will make armature to take heavy current, possibly burning it.

Last Answer : If the field of a D.C. shunt motor gets opened while motor is running the motor will attain dangerously high speed.

Last Answer : If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.

Description : MOSFET uses the electric field of?

Last Answer : MOSFET uses the electric field of gate capacitance.

Description : An electric motor in which both stator field and rotor rotates with same speed is called?

Last Answer : An electric motor in which both stator field and rotor rotates with same speed is called synchronous motor.

Description : If the field of synchronous motor is under excited, power factor will be?

Last Answer : If the field of synchronous motor is under excited, power factor will be lagging.

Description : Is electric potential zero when electric field is zero?

Last Answer : Yes  .If  electric  field  is  zero  then  electric  potential  is  zero  ,  not  even  one.

Description : What is the direction of the induced electric field?

Last Answer : It  is  in  opposite  direction   to  the  one  that   produced  it.

Description : Can the electric field between two positive charges be zero?

Last Answer : It  can  only  if  they  have  equal  charges.

Description : What is the direction of the electric field?

Last Answer : Electric   field    is  at   right angle   widh  flow  of  current  (right  hand   rule).

Description : From which material field coils of DC generator are made of?

Last Answer : Field coils of DC generator are usually made of copper.

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