Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to ________________ boiling ?

Related Mcqs:

1. Trouton’s ratio is given by (where λb, = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K) ___________________?

   A. λb/Tb
   B. Tb/λb
   C. √(λb/Tb)
   D. √(Tb/λb)

2. The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 – T2)/T1. The co-efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2 is given by__________________?

   A. T1/(T1-T2)
   B. T2/(T1-T2)
   C. T1/T2
   D. T2/R1

3. In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is_______________?

   A. More
   B. Less
   C. Same
   D. Unpredictable; depends on the particular reaction

4. Heat of solution in a system in which both solute and solvent are liquids is termed as_________________?

   A. Heat of solvation
   B. Heat of hydration
   C. Standard integral heat of solution
   D. Heat of mixing

5. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is____________________?

   A. 100,000 kW
   B. 160,000 kW
   C. 200,000 kW
   D. 320,000 kW

6. Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is ___________________?

   A. 0
   B. ∞
   C. +ve
   D. -ve

7. Free energy, fugacity and activity co-efficient are all affected by change in the temperature. The fugacity co-efficient of a gas at constant pressure ______________ with the increase of reduced temperature?

   A. Decreases
   B. Increases
   C. Remains constant
   D. Decreases logarithmically

8. Pick out the wrong unit conversion of mass transfer co-efficient?

   A. 1 lb/hr.ft3.atm. = 4.8182 kg/hr.m2.bar
   B. 1 kg/hr.m2.atm= 0.98687 kg/hr. m .bar
   C. 1 lb/hr.ft2 = 4.8823 kg/hr.m2
   D. 1 kg/hr.m2 = 4.8823 lb/hr.ft2

9. A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect ?

   A. Vapor compression cycle using expansion valve
   B. Air refrigeration cycle
   C. Vapor compression cycle using expansion engine
   D. Carnot refrigeration cycle

10. A man exposed to excessive noise level in the working environment may suffer from____________________?

    A. Hearing loss
    B. Rupture of ear drum
    C. Nervousness & fatigue
    D. All A., B. & C.