The falling rate period in the drying of a solid is characterised by

The drying time between fixed moisture contents within the 'constant rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid )

A

$$\sqrt {\text{T}} $$

B

T

C

T^1.5

D

T³

Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant

A

Humidity

B

Velocity

C

Temperature

D

All of the above

In the constant rate period of the rate of drying curve for batch drying,

A

Cracks develop on the surface of the solid

B

Rate of drying decreases abruptly

C

Surface evaporation of unbound moisture occurs

D

None of these

During constant rate drying period, vaporisation rate per unit drying surface area

A

Decreases with time

B

Increases with time

C

Does not change with time

D

Does not affect the moisture content of the wet solid

Occurrence of 'case hardening' during drying of a high moisture solid cake __________ the drying rate.

A

Increases

B

Decreases

C

Does not affect

D

Exponentially increases

A solid material shows case hardening properties while drying. Which of the following should be controlled to control the drying process?

A

Flow rate of inlet air

B

Relative humidity of outlet air

C

Humidity of inlet air

D

Temperature of the solid

With increase in the mass velocity of the gas, the rate of drying during the constant rate period __________ , if the conduction and radiation through the solid are negligible.

A

Increases

B

Decreases

C

Remains same

D

Increases linearly

During the constant rate period of drying of a solid,

A

Increased air humidity decreases the rate of drying

B

Increasing the air temperature decreases the drying rate

C

Surface evaporation of unbound moisture occurs

D

None of these

Go and catch the falling star. Here the ‘‘falling’’ is

A

an adverb

B

a preposition

C

an adjective

D

a verb

Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils?

A

Elaiden test

B

Reichart-Meissl value test

C

Henter value test

D

Iodine value test

The falling rate period in the drying of a solid is characterised by

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