A. 180
B. 970
C. 3.97
D. None of these
Related Mcqs:
- Sensible heat absorbed by 1 lb of water when it is heated from 32 to 212°F may be around ______________ BTU?
A. 180
B. 970
C. 3.97
D. Data insufficient, can’t be predicted - A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m2.°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be__________________?
A. Greater than that for un-insulated steam pipe
B. Less than that of the un-insulated steam pipe
C. Equal to that of the un-insulated steam pipe
D. Less than the steam pipe with 5 cms insulation - An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a_________________?
A. Boiler
B. Heat exchanger
C. Recuperator
D. Regenerator - 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 - Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient for the cooling water, whether on shell side or tube side is the same. The best arrangement is_____________?
A. Vertical heat exchanger with steam on tube side
B. Vertical heat exchanger with steam on shell side
C. Horizontal heat exchanger with steam on tube side
D. Horizontal heat exchanger with steam on shell side - 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 - Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is________________?
A. Finned tube heat exchanger with air inside and steam outside
B. Finned tube heat exchanger with air outside and steam inside
C. Shell and tube heat exchanger with air inside tubes and steam on shell side
D. Shell and tube heat exchanger with air on shell side and steam inside tubes - One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to________________?
A. Heat the water from 0°C to 100°C
B. Evaporate the water
C. To superheat the steam
D. Data insufficient, can’t be predicted - The maximum heat transfer co-efficient from steam heating will be attained when the steam is_________________?
A. Supersaturated
B. Saturated
C. Wet
D. None of these - Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer across an equal area held at the________________?
A. Surrounding temperature
B. Average temperature of the fin
C. Temperature of the fin end
D. Constant temperature equal to that of the base
