A. The better insulation material should be put just next to pipe (i.e., inside)
B. The better insulating material should be put outside
C. Either of the insulating material could be put on either side
D. Steam temperature is considered before deciding as to which insulating material is to be put
inside (i.e., just next to the pipe)
Related Mcqs:
- The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe) ?
A. A
B. D
C. 1/A
D. 1/A2 - Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of ______________ will facilitate the most accurate measurement of the temperature ?
A. Copper
B. Steel
C. Aluminium
D. Brass - Latent heat of dry steam at atmospheric pressure is 539 Kcal/kg; which _____________ with increase in the pressure of steam?
A. Decreases
B. Increases
C. Remain same
D. May increase or decrease - Which of the following parameters is not responsible for the heat loss from a hot steam carrying bare pipe surface located in a room without fans ?
A. Emissivity of pipe surface
B. Diameter & length of the pipe
C. Temperature of hot pipe surface & that of air in the room
D. None of these - A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of thermal conductivity 0.14 W/m.K and thickness ______________ metre?
A. 0.01
B. 0.1
C. 0.25
D. 0.5 - A reduction in thermal resistance during heat transfer does not occur in the___________________?
A. Convection heat transfer by stirring the fluid and cleaning the heating surface
B. Conduction heat transfer by reduction in the material thickness and increase in the thermal
conductivity
C. Radiation heat transfer by increasing the temperature and reducing the emissivity
D. None of these - What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively ?
A. 2
B. 8
C. 10
D. 40 - Electrical conductivities of semi-conductors are of the order of ______________ ohm/cm ?
A. 10-3
B. 103
C. 10-15
D. 1015 - Which of the following phenomenon will exhibit the minimum heat transfer ?
A. Boiling
B. Forced convection in air
C. Free convection in air
D. Conduction in air - . The effect of friction on the flow of steam through a nozzle is to decrease the _______________ of steam?
A. Wetness
B. Mass flow rate
C. Both A & B
D. Neither A nor B
