Chemical Engineering Archives

3871. A heterogeneous reactor is the one, in which the moderator and the

coolant are different materials.

coolant are present in different phases (e.g., heavy water and graphite).

fuel are present in different phases (e.g. uranium and heavy water).

none of these.

✅ The correct answer is option C.

3872. Bubble cap tray is the most commonly used tray in large distillation column, because

of its flexibility and nearly constant efficiency under varying conditions of operation.

it incurs less pressure drop as compared to any other try designed for the same duty.

it eliminates the foaming and entrain-ment tendency during operation.

none of these.

✅ The correct answer is option A.

3873. Pick out the wrong statement pertaining to ‘Horton sphere’ used for the storage of liquid ammonia.

Diameter of Horton sphere is normally 6 to 25 metres and it is supported by 6 to 12 nos. tubular or rolled section column.

Thickness of spherical shell is half that of the cylinderical vessel under same operating pressure condition. Besides, the ratio of surface area to volume is less for sphere than any other shape ; hence insulation required is less.

Horton sphere is used for the storage of gases and volatile liquid at a moderate pressure of 1 to 10 kg/cm2 .

Horton sphere is used for the storage of liquid at sub-zero temperature at very high pressure upto 200 kg/cm2 .

✅ The correct answer is option D.

3874. The time required for half of the __________ of a radioactive isotope to decay is called its half life.

nuclei

electrons

protons

neutrons

✅ The correct answer is option A.

3875. The amount of a radioisotope remaining undecayed after a time equal to four times its half life, will be __________ percent.

3.125

6.25

12.5

✅ The correct answer is option B.

3876. Which of the following is artificially produced as it does not occur in nature ?

Uranium-235

Uranium-233

Plutonium-239

Both (b) and (c)

✅ The correct answer is option D.

3877. Diameter of bubble caps used in high pressure columns is __________ as compared to that used in identical vacuum columns.

less

same

either (a) or (b); no generalisation can be made

✅ The correct answer is option B.

3878. The minimum shell thickness for tank ≤ 15 metres diameter is limited to __________ mm, for reasons of elastic stability.

✅ The correct answer is option B.

3879. First experimental observation of nuclear fission was done by

Plane

Rutherford

Fermi

Hahn and Strassman

✅ The correct answer is option C.

3880. The type of pump used for the recirculation of molten sodium coolant in liquid metal cooled reactor is a/an __________ pump.

electromagnetic

reciprocating

centrifugal

volute

✅ The correct answer is option A.