Spherical shaped pressure vessel is considered to be the most ideal, because it can

withstand higher pressure for a given metallic shell thickness.
be fabricated very easily.
be designed without wind load considerations.
be supported very easily.
✅ The correct answer is option A.

Generally, elliptical dished heads

are manufactured on 2:1 ratio of major to minor axis and is recommended to be used for pressure vessels operating above a pressure of 1.5 MN/m2 .
resist half the pressure rating compared to hemi spherical head provided on the cylindrical shell of the same thickness and diameter.
are approximately as strong as seamless cylindrical shell having the corresponding I.D and O.D.
all (a), (b) and (c)
✅ The correct answer is option D.

Smoker’s equation for the calculation of number of equilibrium stages in a continuous binary distillation column is used, when the

relative volatility is close to one (e.g., separation of close boiling isomers).
feed is not at its bubble point.
number of equilibrium stages in only stripping section is to be calculated.
number of equilibrium stages required is likely to be very small.
✅ The correct answer is option A.