Heating And Welding MCQ

Test your knowledge with important Heating And Welding MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Heating And Welding MCQs at Bissoy

• In direct arc furnace, which of the following has high value?
  ক

  Current

  খ

  Voltage

  গ

  Power factor

  ঘ

  All of the above
• Due to which of the following reasons it is desirable to have short arc length?
  ক

  To achieve better heating

  খ

  To increase the life of roof refractory

  গ

  To have better stirring action

  ঘ

  All of the above
• For intermittent work which of the following furnaces is suitable?
  ক

  Indirect arc furnace

  খ

  Core less furnace

  গ

  Either of the above

  ঘ

  None of the above
• Which of the following will happen if the thickness of refractory wall of furnace is increased?
  ক

  Heat loss through furnace wall will increase

  খ

  Temperature inside the furnace will fall

  গ

  Temperature on the outer surface of furnace walls will drop

  ঘ

  Energy consumption will increase
• In a domestic cake baking oven the temperature is controlled by
  ক

  Voltage variation

  খ

  Thermostat

  গ

  Autotransformer

  ঘ

  Series-parallel operation
• Which of the following is an advantage of heating by electricity?
  ক

  Quicker operation

  খ

  Higher efficiency

  গ

  Absence of flue gases

  ঘ

  All of the above
• In heating the ferromagnetic material by induction heating, heat is produced due to
  ক

  Induced current flow through the charge

  খ

  Hysteresis loss taking place below Curie temperature

  গ

  Due to hysteresis loss as well as eddy current loss taking place in the charge

  ঘ

  None of the above factors
• Resistance variation method of temperature control is done by connecting resistance elements in
  ক

  Series

  খ

  Parallel

  গ

  Series-parallel connections

  ঘ

  All of the above ways
• In an electric room heat convector the method of heating used is Resistance heating
  ক

  True

  খ

  False
• It is desirable to operate the arc furnaces at power factor of
  ক

  Zero

  খ

  0.707 lagging

  গ

  Unity

  ঘ

  0.707 leading
• Which of the following methods is used to control temperature in resistance furnaces?
  ক

  Variation of resistance

  খ

  Variation of voltage

  গ

  Periodical switching on and off of the supply

  ঘ

  All of the above methods
• By which of the following methods the temperature inside arcane can be varied?
  ক

  By disconnecting some of the heating elements

  খ

  By varying the operating voltage

  গ

  By varying the current through heating elements

  ঘ

  By any of the above method
• Which of the following insulating materials was suitable for low temperature applications?
  ক

  Asbestos paper

  খ

  Diatomaceous earth

  গ

  80 percent magnesia

  ঘ

  Cork
• Direct arc furnaces have which of the following power factors?
  ক

  Unity

  খ

  Low, lagging

  গ

  Low, leading

  ঘ

  Any of the above
• Which of the following devices is necessarily required for automatic temperature control in a furnace?
  ক

  Thermostat

  খ

  Thermocouple

  গ

  Autotransformer

  ঘ

  Heating elements of variable resistance material
• ________ is used for heating non-conducting materials.
  ক

  Eddy current heating

  খ

  Arc heating

  গ

  Induction heating

  ঘ

  Dielectric heating
• Induction heating process is based on which of the following principles?
  ক

  Thermal ion release principle

  খ

  Nucleate heating principle

  গ

  Resistance heating principle

  ঘ

  Electromagnetic induction principle
• In the indirect resistance heating method, maximum heat-transfer takes place by
  ক

  Radiation

  খ

  Convection

  গ

  Conduction

  ঘ

  Any of the above
• Ajax Wyatt furnace is started when
  ক

  It is filled below core level

  খ

  It is filled above core level

  গ

  It is fully empty

  ঘ

  None of the above
• The process of heat transfer during the re-entry of satellites and missiles, at very high speeds, into earth?s atmosphere is known as
  ক

  Ablation

  খ

  Radiation

  গ

  Viscous dissipation

  ঘ

  Irradiation
• Method has leading power factor
  ক

  Resistance heating

  খ

  Dielectric heating

  গ

  Arc heating

  ঘ

  Induction heating
• In resistance heating highest working temperature is obtained from heating elements made of
  ক

  Nickel copper

  খ

  Nichrome

  গ

  Silicon carbide

  ঘ

  Silver
• Which of the following has the highest value of thermal conductivity?
  ক

  Water

  খ

  Steam

  গ

  Solid ice

  ঘ

  Melting ice
• ________ has the highest value of thermal conductivity.
  ক

  Copper

  খ

  Aluminium

  গ

  Brass

  ঘ

  Steel
• Induction heating takes place it which of the following?
  ক

  Insulating materials

  খ

  Conducting materials which are magnetic

  গ

  Conducting materials which are non-magnetic

  ঘ

  Conducting materials which may or may not be magnetic
• In arc furnace the function of choke is
  ক

  To stabilize the arc

  খ

  To improve power factor

  গ

  To reduce severity of the surge

  ঘ

  None of the above
• Which of the following methods of heating is not dependent on the frequency of supply?
  ক

  Induction heating

  খ

  Dielectric heating

  গ

  Electric resistance heating

  ঘ

  All of the above
• Hysteresis loss and eddy current loss are used in
  ক

  Induction heating of steel

  খ

  Dielectric heating

  গ

  Induction heating of brass

  ঘ

  Resistance heating
• For radiant heating around 2250°C, the heating elements are made of
  ক

  Copper alloy

  খ

  Carbon

  গ

  Tungsten alloy

  ঘ

  Stainless steel alloy
• Heat is transferred simultaneously by condition, convection and radiation
  ক

  Inside boiler furnaces

  খ

  During melting of ice

  গ

  Through the surface of the insulted pipe carrying steam

  ঘ

  From refrigerator coils to freezer of a refrigerator