Engineering :: Mass Transfer

@ : Home > Chemical Engineering > Mass Transfer

31.

The relative saturation of an unsaturated mixture of vapour and gas depends on

A.	the composition of the mixture	B.	the temperature of the mixture
C.	the nature of the vapour	D.	all of the above

32.

For a vapour-gas mixture the wet and dry-bulb temperature are 20?C and 35?C respectively if the mixture is heated to 50?C at constant pressure the wet bulb temperature will be

A.	20?C	B.	>20?C
C.	<20?C	D.	? 20?C

33.

At the boiling point of the liquid at the prevailing pressure the saturated absolute humidity becomes

A.	one	B.	zero
C.	infinity	D.	none of the above

34.

The dew point of an unsaturated mixture of water vapour and air at constant temperature and pressure

A.	does not change with change in absolute humidity	B.	increases with increase in absolute humidity
C.	decreases with increase in absolute humidity	D.	decreases linearily with increase in absolute humidity.

35.

The steady-state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called

A.	dry-bulb temperature	B.	dew point
C.	wet-bulb temperature	D.	bubble point

36.

For any vapour-gas mixture the adiabatic saturation curve is

A.	straight line	B.	slightly concave upward
C.	slightly concave downward

37.

The psychrometric ratio is defined as

A.	hG/ky	B.	ky/hG
C.	hG/ky Cs	D.	NSc/NPr

38.

The Lewis number of a mixture is defined as

A.	NPr/NSc	B.	NPr NSc
C.	NSc/NPr	D.	Cs (NSc/NPr)

39.

For the system air-water vapour hG/ky Cs is approximately equal to

A.	1	B.	0.24
C.	2.4	D.	3

40.

The lewis number of a mixture is one when mass diffusivity is equal to

A.	momentum diffusivity	B.	thermal diffusivity
C.	thermal conductivity	D.	1/thermal diffusivity