HomeElectrical material Ques part 2Electrical material Ques part 2 Electrical material Ques part 2 Education April 09, 2023 0 1➤ Pure metals generally haveHigh conductivity and large temperature coefficient Low conductivity and zero temperature coefficient Low conductivity and high temperature coefficient High conductivity and low temperature coefficient 2➤ What is the magnetic susceptibility of an ideal super conductor?1-1Infinity 03➤ The dc resistivity and permeability exhibited by a type 1 super conductor are respectively 0,00,11,11,04➤ The materials not having negative temperature coefficient of resistivity areSemiconductorsMetalsInsulators All of these5➤ If the diameter of a copper wire is increased by two times keeping it's terminal voltage same,then the drift velocity willRemains unchanged Becomes twiceBecome halfBecomes four times 6➤ Bohr magneton is unit ofMagnetic energy PolarisibilityHysteresis lossPermanent dipole moment due to spin7➤ Enameled wires are preferred to cotton-covered wires toReduce the resistivity Improve heat dissipation Withstand higher temperature All of these8➤ Magnetic field of earth has no vertical component atMagnetic equatorLongitude 45°Latitude 45°Magnetic poles9➤ All magnetic material lose their magnetic properties when Cooled at low temperature Kept in an aluminium boxKept in vaccumHeated to high temperature 10➤ Ferromagnetic property may be explained on the basis ofDomain theoryFaraday's theory Curie-weiss theoryEinstein theory 11➤ When the temperature of magnetic material is raised above the Curie temperature, it behaves similar toDiamagnetic material Paramagnetic material Ferrimagnetic materials Antiferromagnetic materials 12➤ Orbital magnetic moment of an electron, in an atom, is of the order of1.0 Bohr magneton 0.1 Bohr magneton 10 Bohr magneton 100 Bohr magneton 13➤ A permeable substance is one Which is strong magnetic Which is weak magnetic Through which magnetic lines of force passes easilyWhich is good conductor 14➤ Exposure of insulating material to moisture causes increase inDielectric strength Dielectric lossInsulation resistance All of these 15➤ The ceramic dielectric used in electrical engineering include Cermetvand silicideSilicide and cordierite Porcelain and cermetPorcelain and cordierite 16➤ Iron is a Ferromagnetic Ferrimagnetic Antiferromagnetic Paramgnetic 17➤ With the increase in temperature magnetic susceptibility of a ferromagnetic materials willDecrease Increase Increase initially and then decrease Reamains constant 18➤ Paramagnetic susceptibility of a material Increase linearly with temperature Decrease linearly with temperature Decrease linearly with (1/T)Increase linearly with(1/T)19➤ Which one of the following is not a ferromagnetic materials CobaltBismuth IronNickel 20➤ Air exhibitsParamagnetismFerromagnetismFerrimagnetismAntiferromagnetism21➤ The magnetic field require to reduce the residual magnetization to zero is calledRetentivity Hysteresis Coercivity Saturation 22➤ On which of the following factors does hysteresis loss not depend?Neel temperature Frequency of the fieldVolume of the material Magnetic field intensity 23➤ Commonly used dielectric in electrolytic capacitors isAll of the belowCadmium nitrideMagnetism oxideAluminium oxides24➤ _______is employed for winding of coils for DC motor startersConstantanCopperNichromeAluminium 25➤ Which one of the following is not a permanent magnetic material Silicon iron AlnicoCobalt steelChromium steel26➤ Mettalic copper isParamgnetic substance Ferromagnetic substance Diamagnetic substance Ferrimagnetic substance 27➤ The coercive force in a ferromagnetic materials is related toArea enclosed by B-H loopIntercept on the positive B axis of The B-H loopIntercept on the negative B axis of The B-H loopMaximum value of B on B-H loop SubmitYour score is Tags Electrical material Ques part 2 Newer Older