Boiling of milk in an open vessel is an example of ______________ boiling?

Related Mcqs:

1. In case of _______________ boiling, the liquid temperature is below the saturation temperature and the boiling takes place in the vicinity of the heated surface?

   A. Nucleate
   B. Local
   C. Pool
   D. Saturated

2. Boiling point elevation for a strong and concentrated solution is found by Duhring’s rule, which states that at the same pressure, the boiling point of a solution is a linear function of the _______________ of pure water?

   A. Boiling point
   B. Dynamic viscosity
   C. Kinematic viscosity
   D. Density

3. 1000 Kg of liquid at 30°C in a well stirred vessel has to be heated to 120°C, using immersed coils carrying condensing steam at 150°C. The area of the steam coils is 1.2 m2 and the overall heat transfer co-efficient to the liquid is 1500 W/m2.°C. Assuming negligible heat loss to the surrounding and specific heat capacity of the liquid to be 4 kJ/kg.°C, the time taken for the liquid to reach desired temperature will be__________________?

   A. 15 min
   B. 22 min
   C. 44 min
   D. 51 min

4. Heat flux increases with temperature drop beyond the Leiden frost point in the plot of heat flux vs. temperature drop for a boiling liquid, because___________________?

   A. Convection becomes important
   B. Conduction becomes important
   C. Radiation becomes important
   D. Sub-cooled boiling occurs

5. Boiling point of a solution according to Duhring’s rule is a linear function of the _____________ of water?

   A. Boiling point (at the same pressure)
   B. Viscosity
   C. Density
   D. Thermal conductivity

6. It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is____________________?

   A. 3.06 × 105
   B. 6.12 × 105
   C. 7.24 × 105
   D. 9.08 × 105

7. In sub-cooled boiling ?

   A. Temperature of the heating surface is less than the boiling point of the liquid
   B. Temperature of the heating surface is more than the boiling point of the liquid
   C. Bubbles from heating surface are absorbed by the mass of the liquid
   D. Very large vapour space is necessary

8. In the free convection regime of pool boiling, the heat flux is proportional to__________________?

   A. Δt1/2
   B. Δt2
   C. Δt5/4
   D. Δt

9. When vaporisation takes place through a blanketting film of gas, the phenomenon is termed as ___________________ boiling?

   A. Pool
   B. Nucleate
   C. Transition
   D. Film

10. Film boiling occurs at ________________ pressure?

    A. Atmospheric
    B. Sub-atmospheric
    C. Negative
    D. Very high