50 Important Electrical Heating MCQ Question and Answer | PDF Free Download
1.Which of the following is an advantage of heating by electricity?
- AQuicker operation
- BHigher efficiency
- CAbsence of flue gases
- DAll of the above
2.Which of the following heating method has maximum power factor?
- AArc heating
- BDielectric heating
- CInduction heating
- DResistance heating
3.which of the following heating method has leading power factor?
- AResistance heating
- BDielectric heating
- CArc heating
- DInduction heating
4.which is used for heating non-conducting materials?
- AEddy current heating
- BArc heating
- CInduction heating
- DDielectric heating
5.Which of the following method of heating is not dependent on the frequency of supply?
- AInduction heating
- BDielectric heating
- CElectric resistance heating
- DAll of the above
6.When a body reflects entire radiation incident on it, then it is known as
- AWhite body
- BGrey body
- CBlack body
- DTransparent body
7.For the transmission of heat from one body to another
- ATemperature of the two bodies must be different
- BBoth bodies must be solids
- CBoth bodies must be in contact
- DAt least one of the bodies must have some source of heating
8.Which of the following has the highest value of thermal conductivity?
- ACopper
- BAluminium
- CBrass
- DSteel
9.Heat transfer by condition will not occur when
- ABodies are kept in vacuum
- BBodies are immersed in water
- CBodies are exposed to thermal radiations
- DTemperatures of the two bodies are identical
10.A perfect black body is one which
- ATransmits all incident radiations
- BAbsorbs all incident radiations
- CReflects all incident radiations
- DAbsorbs, Reflects and Transmits all incident radiations
11.Heat is transferred simultaneously by condition, convection and radiation
- AInside boiler furnaces
- BDuring melting of ice
- CThrough the surface of the insulted pipe carrying steam
- DFrom refrigerator coils to freezer of a refrigerator
12.The process of heat transfer during the re-entry of satellites and missiles, at very high speeds, into earth?s atmosphere is known as
- AAblation
- BRadiation
- CViscous dissipation
- DIrradiation
13.Which of the following has the highest value of thermal conductivity?
- AWater
- BSteam
- CSolid ice
- DMelting ice
14.Induction heating process is based on which of the following principles?
- AThermal ion release principle
- BNucleate heating principle
- CResistance heating principle
- DElectro-magnetic induction principle
15.Which of the following insulating materials is suitable for low temperature applications?
- AAsbestos paper
- BDiatomaceous earth
- C80 percent magnesia
- DCork
16.A non-dimensional number generally associated with natural convection heat transfer is
- APrandtl number
- BGrashoff number
- CPecelet number
- DNusselt number
17.The temperature inside a furnace is usually measured by
- AOptical pyrometer
- BMercury thermometer
- CAlcohol thermometer
- DAny of the above
18.Which of the following will happen if the thickness of refractory wall of furnace is increased?
- AHeat loss through furnace wall will increase
- BTemperature inside the furnace will fall
- CTemperature on the outer surface of furnace walls will drop
- DEnergy consumption will increase
19.The material of the heating element for a furnace should have
- ALower melting point
- BHigher temperature co-efficient
- CHigh specific resistance
- DAll of the above
20.In a resistance furnace the atmosphere is ____________
- AOxidizing
- BDeoxidising
- CReducing
- DNeutral