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61.

The Reynolds analogy states that Where f = Fanning friction factor

A.	NSt = f/8	B.	NSt = f/2
C.	NPr = f/4	D.	NSt = f

62.

Reynolds and Prandtl analogies are exactly same for

A.	Npr = 0.7	B.	NPr = 1
C.	NPr = 0.6	D.	NPr > 1

63.

When the Prandtl number is greater than unity the thermal boundary layer

A.	is thinner than the hydrodynamic boundary layer	B.	is thicker than the hydrodynamic boundary layer
C.	and the hydrodynamic boundary are identical	D.	disappears

64.

The Colburn/factor for heat transfer is defined as

A.	NSt NPr	B.	NSt NPr 1/3
C.	NSt NPr 2/3	D.	NSt NPr 3/2

65.

The Reynolds analogy

A.	applies only to fluids for which the Prandtl number is unity	B.	applies over a range of Parandtl numbers from 0.6 to 120
C.	can be used for situations where form drag appears	D.	cannot be used for situations where wall drag appears

66.

For laminar fully developed constant property flow in a pipe at uniform heat flux the Nusselt number is

A.	3.656	B.	2
C.	4.364	D.	0.7

67.

For laminar fully developed constant property flow in a pipe at constant wall temperature the Nusselt number is

A.	2	B.	4.354
C.	0.7	D.	3.656

68.

The Prandtl number for liquid metals is of the order of

A.	1	B.	10
C.	10?	D.	10

69.

The Colburn analogy states that where f = Fanning friction factor

A.	NSt = f/2	B.	NSt NPr = f/2
C.	NSt NPr 2/3 = f/2	D.	NSt NPr 2/3 = f/8

70.

Dittus-Boelter equation NNu = 0.023 (NRe)0.8(NPr)n where n = 0.4 for heating the fluid and n = 0.3 for cooling the fluid is applicable for

A.	10.000 < NRe < 1.2 x 105	B.	0.7 < NPr < 120
C.	L/D > 60	D.	all the above