Heating the Hypo-eutectoid steels to 30°C above the upper critical temperature line, soaking at that temperature and then cooling slowly to the room temperature to form a pearlite & ferrite structure is called_______________________?

Related Mcqs:

1. Eutectoid composition of carbon steel at room temperature is___________________?

   A. Cementite
   B. Pearlite
   C. Martensite
   D. Ferrite

2. Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the ______________ temperature of air?

   A. Wet bulb
   B. Dry bulb
   C. Saturation
   D. Dew point

3. Steels with high carbon equivalent have poor Weldability, because in these steels during welding________________?

   A. Carbon and other alloying elements get oxidised from the weld pool
   B. Excessive ferrite forms in the heat affected zone leading to poor toughness of the weld
   C. Martensite forms in the heat affected zone leading to poor toughness/ductility of the weld
   D. Segregation of carbon and other element occurs in the weld pool leading to poor properties of
   the weld

4. Heating of ferromagnetic materials to a temperature above Curie temperature makes it ________________________?

   A. Insulator for heat & electricity transmission
   B. Ferritic
   C. Behave like paramagnetic materials
   D. Superconductor

5. _______________ number determines whether the fluid flow in an open channel is super-critical, critical or sub-critical ?

   A. Mach
   B. Reynolds
   C. Froude
   D. Weber

6. The heat released by cooling one mole of copper from 400 K to room temperature (300 K) is (assume : Cp of copper is 23 J K-1mole-1) ?

   A. 2300 J
   B. 4600 J
   C. 230 J
   D. 2.3 × 106 J

7. The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K) ?

   A. T
   B. 1/T
   C. T2
   D. 1/T2

8. Pearlite comprises of__________________?

   A. 87% cementite & 13% Fe
   B. 87% ferrite & 13% cementite
   C. 93.33% ferrite & 6.67% C
   D. 87% ferrite & 13% C

9. Evaporative cooling process employs a combination of cooling and humidification in which the____________________?

   A. Sensible heat is added
   B. Sensible heat is removed and the latent heat is added
   C. Latent heat is removed
   D. Sensible heat is added and latent heat is removed

10. The minimum temperature to which the water can be cooled in a cooling tower is the ______________ temperature of air?

    A. Ambient
    B. Dry bulb
    C. Dew point
    D. Wet bulb