In electric press, mica is used because it is _________ conductor of heat but/and __________ conductor of electricity?

Related Mcqs:

1. In an electric press mica is used_____________?

   A. as an insulator
   B. as a device for power factor improvement
   C. for dielectric heating
   D. for induction heating

2. In an electric room heat convector the method of heating used is______________?

   A. arc heating
   B. resistance heating
   C. induction heating
   D. dielectric heating

3. Which of the following is an advantage of heating by electricity ?

   A. Quicker operation
   B. Higher efficiency
   C. Absence of flue gases
   D. All of the above

4. For the transmission of heat from one body to another__________?

   A. temperature of the two bodies must be different
   B. both bodies must be solids
   C. both bodies must be in contact
   D. at least one of the bodies must have some source of heating

5. Heat is transferred simultaneously by condition, convection and radiation_____________?

   A. inside boiler furnaces
   B. during melting of ice
   C. through the surface of the insulted pipe carrying steam
   D. from refrigerator coils to freezer of a refrigerator

6. Heat transfer by condition will not occur when____________?

   A. bodies are kept in vacuum
   B. bodies are immersed in water
   C. bodies are exposed to thermal radiations
   D. temperatures of the two bodies are identical

7. In the indirect resistance heating method, maximum heat-transfer takes place by____________?

   A. radiation
   B. convection
   C. conduction
   D. any of the above

8. The process of heat transfer during the reentry of satellites and missiles, at very high speeds, into earth’s atmosphere is known as_______________?

   A. ablation
   B. radiation
   C. viscous dissipation
   D. irradiation

9. A non-dimensional number generally associated with natural convection heat transfer is____________?

   A. Prandtl number
   B. Grashoff number
   C. Pecelet number
   D. Nusselt number

10. In heating the ferromagnetic material by induction heating, heat is produced due to_____________?

    A. induced current flow through the charge
    B. hysteresis loss taking place below curie temperature
    C. due to hysteresis loss as well as eddy current loss takingplace in the charge
    D. none of the above factors