CHEMICAL ENGINEERING

Question: On-off control
[A].

fully opens the final control element, when the measured variable is below the set point.

[B].

fully closes the final control element, when the measured variable is above the set point.

[C].

is a two position control (fully open or fully closed) control adequate to control a process with slow reaction and minimum dead time or transfer lag.

[D].

none of these.

Answer: Option C

Explanation:

No answer description available for this question.

Question: A controller action in which there is a con-tinous relation between the values of controlled variable and the rate of change of conrolled output signal is called the __________ action.
[A].

proportional

[B].

integral

[C].

derivative

[D].

none of these

Answer: Option B

Explanation:

No answer description available for this question.

Question: Difference at any instant between the value of the controlled variable and the set point is called the
[A].

deviation

[B].

derivative time

[C].

error ratio

[D].

differential gap

Answer: Option A

Explanation:

No answer description available for this question.

Question: Device used as a standard for the calibration of pressure gauges is a
[A].

bellow

[B].

diaphragm

[C].

dead weight pressure tester

[D].

mercury manometer

Answer: Option C

Explanation:

No answer description available for this question.

Question: Out of the following, the highest emf for a given temperature is generated by the __________ thermocouple.
[A].

chromel – alumel

[B].

iron – constantan

[C].

platinum – platinum + rhodium

[D].

copper-constantan

Answer: Option B

Explanation:

No answer description available for this question.

Question: __________ number is sometimes used in place of Grashoff number in free convection heat transfer.
[A].

Stanton

[B].

Brinkman

[C].

Rayleigh

[D].

Nusselt

Answer: Option C

Explanation:

No answer description available for this question.

Question: Heat transfer by radiation from a hot body will be most rapid, if its surface is __________ because of its higher emissivity.
[A].

white & rough

[B].

black & rough

[C].

white & polished

[D].

black & polished

Answer: Option B

Explanation:

No answer description available for this question.

Question: Parallel straight line pattern of temperature distribution for both hot and cold fluids is observed in case of heat exchanger of the type
[A].

parallel flow with equal heat capacities.

[B].

counter flow with equal heat capacities.

[C].

counter flow with unequal heat capacities.

[D].

parallel flow with unequal heat capacities.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as
[A].

Re0.5, Re0.8

[B].

Re0.8, Re-0.5

[C].

Re0.8, Re0.5

[D].

Re-0.8, Re0.5

Answer: Option C

Explanation:

No answer description available for this question.

Question: Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as
[A].

Gr0.25, Gr

[B].

Gr0.25, Gr0.33

[C].

Gr, Gr0.25

[D].

Gr0.33, Gr0.25

Answer: Option A

Explanation:

No answer description available for this question.