The ability of materials to become polarized under an applied electric field is called Paraelectricity
Description : The electric breakdown strength of insulating materials depends on (A) Nature of applied voltage (B) lmperfection of dielectric material (C) Pressure, temperature and humidity (D) All or these
Last Answer : The electric breakdown strength of insulating materials depends on (A) Nature of applied voltage (B) lmperfection of dielectric material (C) Pressure, temperature and humidity (D) All or 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 : 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 : 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 : MOSFET uses the electric field of?
Last Answer : MOSFET uses the electric field of gate capacitance.
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 : Those materials are well suited for making permanent magnets which have _____ retentivity and _______ coercivity.
Last Answer : Those materials are well suited for making permanent magnets which have high retentivity and high coercivity.
Description : State the type of insulating materials under Class Y and Class B.
Last Answer : The type of insulating materials under Class Y : 1. Cotton 2. Silk 3. Paper 4. Rubber 5. PVC The type of insulating materials under Class B: 1. Backelite 2. Impregnated varnish 3. Mica 4. Fiber glass 5. Asbestos
Description : State the insulating materials used in motor. Write temperature class and withstand temperature ranges for them.
Last Answer : The insulating materials used in motor are as belows: 1. Cotton, 2. Silk, or paper, 3. Press board, 4. Resins 5. PVC 6. Cellulose-Fiber, 7. Enameled coating, etc ... Over 180° Mica, porcelain, ceramics, glass quartz, asbestos, treated glass fiber or treated asbestos. etc.
Description : State properties of insulating materials.
Last Answer : (i) Resistivity should be very high. (ii) It should be water resistant. (iii) It should not contain impurities. (iv) It should not be affected chemically and not corroded easily. (v) Its ... It should be mechanically strong (tensile strength should be more). (vii) It should not be porous.
Description : State any four dielectric materials.
Last Answer : Ceramics, distilled water, paper, mica, polyethylene, and glass. Metal oxides
Description : Classify electrical materials.
Last Answer : Classification of electrical materials: i) Conducting Materials ii) Insulating materials iii) Magnetic materials iv) Semiconducting materials
Description : Explain the mechanical properties of insulating materials.
Last Answer : i) Mechanical strength: Mechanical strength depends on temperature and humidity. a) Temperature: High temperature badly affects the mechanical strength of insulating material. While selecting material ... material should have property of easy moulding and machined into required shape and size.
Description : Classify magnetic materials and explain in brief.
Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { ... the absence of external magnetic field. Following are the ferromagnetic materials: Iron, Cobalt, Nickel.
Description : State any four properties of conducting materials.
Last Answer : Electrical properties of conductivity materials: i) Low resistivity. ii) Low temperature coefficient of resistance. iii) High conductivity. iv) Low heat dissipation. Mechanical properties of ... properties of conductivity materials: i) Adequate resistant to corrosion. ii) Low oxidation.
Description : _______ is used for heating non -conducting materials. (1) Eddy current heating (2) Arc heating (3) Induction heating (4) Dielectric heating
Last Answer : Dielectric heating is used for heating non -conducting materials.
Description : Magnetostrictive materials can convert ________ A) Magnetic energy into kinetic energy B) Kinetic energy into magnetic energy C) Both A and B D) None of these
Last Answer : Magnetostrictive materials can convert ________ A) Magnetic energy into kinetic energy B) Kinetic energy into magnetic energy C) Both A and B D) None of these
Description : Those magnetic materials are best suited for making armature and transformer cores which have____permeability and_______hystersis loss.
Last Answer : Those magnetic materials are best suited for making armature and transformer cores which have high permeability and low hystersis loss.
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.
Description : Can you help me with a list of clothing materials? (Details inside!)
Last Answer : answer:Cotton, wool, linen, silk, rayon, polyester, nylon, hemp, microfiber, leather, recycled plastic bottles. Velvet is cotton, nylon or silk with a short pile. Lace is cotton or silk thread that has been arranged in a pattern.
Description : What materials are interior doors made of?
Last Answer : What materials are interior doors made of? The door leaf material is a key component that influences the quality and cost of the door. Interior doors made of walnut or oak look great and ... relevant for office doors, but they are also installed in residential premises if necessary to reduce costs.
Description : Magnetic and Non-magnetic Materials
Last 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 : List any four materials used for pattern making
Last Answer : The various types of materials used are as follows: 1. Wood 2. Metal. 3. Plastic. 4. Plaster. 5. Wax.
Description : The bridge most suited for accurate measurement of relative permittivity of dielectric materials is (A) Carey Foster Bridge (B) Anderson’s bridge (C) Heaviside Bridge modified by Campbell. (D) Schering Bridge.
Last Answer : The bridge most suited for accurate measurement of relative permittivity of dielectric materials is Schering Bridge.
Description : Insulating materials have the function of?
Last Answer : Insulating materials have the function of preventing an open circuit between the voltage source and the load.
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 : 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 : 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 : 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 : Select insulating materials for following parts : (i) Insulation between heating element and base plate of electric iron. (ii) Insulation used over copper or aluminium conductor used for making coils. (iii) Transformer bushings. (iv) Insulation between transmission line and pole.
Last Answer : Parts Insulating Materials Insulation between heating element and base plate of electric iron. Mica Insulation used over copper or aluminium conductor used for making coils. ... Transformer bushings Porcelain Insulation between transmission line and pole. Porcelain
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 : 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 : 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 : 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.
Last Answer : Flashing the field of D.C. generator means creating residual magnetism by a D.C. source.
Last Answer : ni bondha
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.