1) Which of the following fluid can be considered as an ideal fluid?
a. viscous fluid
b. nonviscous fluid
c. compressible fluid
d. all of the above
Answer
Explanation

ANSWER: nonviscous fluid
Explanation: No explanation is available for this question!


2) The Grashof number in natural convection plays same role as
a. Prandtl number (Pr) in forced convection
b. Reynolds number (Re) in forced convection
c. Nusselt number (Nu) in forced convection
d. none of the above
Answer
Explanation

ANSWER: Reynolds number (Re) in forced convection
Explanation: No explanation is available for this question!


3) If there are no externally induced flow velocities, then the Nusselt number (Nu) does not depend upon
a. Prandtl number (Pr)
b. Reynolds number (Re)
c. Grashof number (Gr)
d. none of the above
Answer
Explanation

ANSWER: Reynolds number (Re)
Explanation: No explanation is available for this question!


4) Which of the following condition is correct for natural convection?
a. (Gr / Re ^{2}) = 1
b. (Gr / Re ^{2}) << 1
c. (Gr / Re ^{2}) >> 1
d. none of the above
Answer
Explanation

ANSWER: (Gr / Re^{2}) >> 1
Explanation: No explanation is available for this question!


5) In natural convection, the Nusselt number (Nu) depends on
a. Pr and Re
b. Gr and Re
c. Gr and Pr
d. none of the above
Answer
Explanation

ANSWER: Gr and Pr
Explanation: No explanation is available for this question!


6) What is the ratio of the buoyancy force to the viscous force acting on a fluid called?
a. Prandtl number (Pr)
b. Reynolds number (Re)
c. Nusselt number (Nu)
d. Grashof number (Gr)
Answer
Explanation

ANSWER: Grashof number (Gr)
Explanation: No explanation is available for this question!


7) What is hydrodynamically developed region in fluid flowing inside a pipe?
a. a region where velocity profile of the fluid is partially developed
b. a region where velocity profile of the fluid is fully developed
c. a region where velocity profile of the fluid changes according to the distance
d. none of the above
Answer
Explanation

ANSWER: a region where velocity profile of the fluid is fully developed
Explanation: No explanation is available for this question!


8) Assume fluid flowing in a tube forcefully. The velocity boundary layer develops along the tube. Thickness of this boundary layer increases in the flow direction until the boundary layer reaches the tube centre. This region from the tube inlet to the point at which the boundary layers merge at the centerline is called as
a. laminar entry region
b. hydraulic entry region
c. hydrostatic entry region
d. hydrodynamic entry region
Answer
Explanation

ANSWER: hydrodynamic entry region
Explanation: No explanation is available for this question!


9) Below figure shows a natural convection heat transfer on a horizontal flat plate and fluid is above it. Which condition satisfies the figure below?
a. Plate temperature is lower than the fluid temperature
b. Plate temperature is higher than the fluid temperature
c. Plate temperature is equal to the fluid temperature
d. unpredictable
Answer
Explanation

ANSWER: Plate temperature is higher than the fluid temperature
Explanation: No explanation is available for this question!


10) Assume a natural convection heat transfer on a vertical flat plate surrounded by a fluid. Where will be the fully developed turbulent layer of fluid established, if the plate is hotter than the fluid?
a. At the bottom of the plate
b. At the middle of the plate
c. At the top of the plate
d. Nowhere
Answer
Explanation

ANSWER: At the top of the plate
Explanation: No explanation is available for this question!

