31. A glass tube of smaller diameter is used while performing an experiment for the capillary rise of water because

A. it is easier to see through the glass tube
B. glass tube is cheaper than a metallic tube
C. it is not possible to conduct this experiment with any other tube
D. all of the above

32. The viscosity of a liquid is due to cohesion of its particles.

A. Correct
B. Incorrect

33. A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if

A. length of both the pipes is same
B. diameter of both the pipes is same
C. loss of head and discharge of both the pipes is same
D. loss of head and velocity of flow in both the pipes is same

34. In a footstep bearing, if the speed of the shaft is doubled, then the torque required to overcome the viscous resistance will be

A. double
B. four times
C. eight times
D. sixteen times

35. The viscosity of water is __________ than that of mercury.

A. higher
B. lower

36. The velocity at which the laminar flow stops is known as

A. velocity of approach
B. lower critical velocity
C. higher critical velocity
D. none of these

37. When a cylindrical vessel, containing some liquid, is rotated about its vertical axis, the liquid surface is depressed down at the axis of its rotation and rises up near the walls of the vessel on all sides. This type of flow is known as

A. steady flow
B. turbulent flow
C. vortex flow
D. uniform flow

38. The Newton’s law of resistance is based on the assumption that the

A. planes of the body are completely smooth
B. space around the body is completely filled with the fluid
C. fluid particles do not exert any influence on one another
D. all of the above

39. The Euler’s equation for the motion of liquids is based upon the assumption that

A. the fluid is non – viscous, homogeneous and incompressible
B. the velocity of flow is uniform over the section
C. the flow is continuous, steady and along the streamline
D. all of the above

40. A weir is usually made of masonry or concrete.

A. Yes
B. No