Chemical Engineering Gate 2018 Questions with Answer

Ques 40 GATE 2018

Consider the following transfer function: G(s) = 3 / (5s + 1)² where, the natural period of oscillation is in min. The amplitude ratio at a frequency of 0.5 rad/min is_____________ (rounded off to second decimal place).

Ques 41 GATE 2018

For a closed-loop system, consider the following transfer functions: process G_p(s) = 2 / (7s +1) ; controller G_c(s) = 2 ; G_m(s) =1 ; G_f(s)=1 The offset in the closed loop response due to a unit step change introduced in the set point of the output variable is ________.

Ques 42 GATE 2018

Economy of evaporators used for concentrating sugarcane juice is

Ques 43 GATE 2018

Two packed towers are designed for the same mass velocity of the gas. The first has liquid and gas flow rates of 30 kg/s and 1.2 kg/s, respectively, while the corresponding flow rates in the second tower are 67.5 kg/s and 1.8 kg/s. The ratio of the design diameter of the wider tower to that of the narrower tower is

Ques 44 GATE 2018

According to the surface renewal theory, the unit of fractional rate of surface renewal is

Ques 45 GATE 2018

For absorption of H2S from a mixture with hydrocarbon vapour into an aqueous alkanolamine solution, the liquid phase mass transfer resistance is

Ques 46 GATE 2018

It is decided to extract A from a feed containing 20 mol% A and 80 mol% B in two ideal cross-current stages as shown below, using equal amount of pure solvent C in each stage.

Ques 47 GATE 2018

A binary distillation column is designed by McCabe-Thiele method to get a distillate mole fraction of 0.9. The enriching section operating line has an intercept with y-axis at 0.3 mole fraction. The ratio of liquid to vapour molar flow rate in the enriching section is _____________ (rounded off to third decimal place).

Ques 48 GATE 2018

A fiberboard sheet (1.5 m × 2.0 m × 15 mm) is being dried by suspending it horizontally in a current of hot, dry air. The edges are insulated so that drying takes place only from the top and bottom surfaces. The wet sheet weighing 16 kg with initial moisture content of 60% loses moisture at a constant rate of 1.25 × 10^-5 kg m^-2 s^-1 until the moisture content falls to 30%. All moisture contents are on dry basis. The time required for drying during constant rate period (in hour) is _____________ (rounded off to third decimal place).

Ques 49 GATE 2018

The humidity of air at a dry-bulb temperature of 65 ºC is 0.025 kg water/kg dry air. The latent heat of vaporization of water at 0 ºC is 2500 kJ/kg. The psychrometric ratio of air is 0.95 kJ (kg dry air)^-1 K^-1. Considering 0 ºC as reference temperature, the enthalpy of air (in kJ/kg) at its adiabatic saturation temperature of 35 ºC is ___________

Ques 50 GATE 2018

Critical speed of a ball mill depends on

Ques 51 GATE 2018

Match the equipment in Column A with the corresponding process in Column B

Ques 52 GATE 2018

In a roll crusher, rolls of diameter 1 m each are set in such a manner that minimum clearance between the crushing surfaces is 15 mm. If the angle of nip is 31^o, the maximum diameter of the particle (in mm) which can be crushed is ____________ (rounded off to third decimal place).