Q.no 21. Which area is used in case of heat flow by conduction through a cylinder
A : Logarithmic mean area
B : Arithmetic mean area
C : Geometric mean area
D : None of these
Q.no 22. Radiosity is the total……… flux leaving the surface
A : Heat
B : Radiant
C : Molar
D : None of these
Q.no 23. In specular reflection the angle of
A : Incident # Reflection
B : Absorption = Transmittion
C : Incident = Reflection
D : Absorption # Transmittion
Q.no 24. Overall thermal resistance for conductive heat transfer through a series of flat resistances is equal to the
A : maximum resistance in the series
B : sum of all resistances
C : average of all resistances
D : minimum resistance presents in the series
Q.no 25. Emissive power is measured in
A : Watt/m2k4
B : Watt/m2
C : watt/m
D : Watt
Q.no 26. Heat flows from one body to other when they have
A : different heat contents
B : different specific heat
C : different atomic structure
D : different temperatures
Q.no 27. Old houses were often built with high ceilings in the rooms so that they would be cooler in the warmer months. This was to take advantage of
A : Convection
B : Conduction
C : Radiation
D : Insulation
Q.no 28. Choose the correct equation
A : Nu = (Re) (Pr) (Gz)
B : Nu = (Re) (Pr) (St)
C : Nu = (Re)(Pr)
D : Nu = (Pr)(St)
Q.no 29. Maximum heat transfer rate is obtained in __ flow
A : Laminar
B : Turbulent
C : Creeping
D : transition region
Q.no 30. The Convective heat transfer coefficient in case of fluid flowing in the tubes is not affected by the tube length/diameter ratio, if the flow is in the __ zone.
A : Laminar
B : transition
C : both ‘a’ & ‘b’
D : highly turbulent
Answer for Question No 21. is a
Answer for Question No 22. is b
Answer for Question No 23. is c
Answer for Question No 24. is b
Answer for Question No 25. is b
Answer for Question No 26. is d
Answer for Question No 27. is a
Answer for Question No 28. is b
Answer for Question No 29. is b
Answer for Question No 30. is d
Leave a comment