List of top Basic Engineering and Science Questions

Which of the following is not a method of source reduction?
Rancidity of oil can be reduced by
Adsorption of acetone from aqueous solution on activated carbon can be represented by the Langmuir equation: \[ \frac{q}{C} = \frac{1}{0.146} + \frac{0.190}{C} \] where \( q \) is the adsorbate loading mol/kg, and \( C \) is solute concentration in aqueous solution mol/m³. The maximum adsorbate loading in kg acetone/kg carbon is
Mass transfer zone in fixed bed adsorber is
Favourable adsorption isotherms are those
Which one of the following adsorbents is preferred for adsorbing components from aqueous solutions and moist gases because of its poor affinity with water?
The Antoine constant for the component is given by \( A = 16.678, B = 3640.2, C = 219.61 \). The pressure (kPa) for the temperature 373 K is
The numerical technique used to solve simultaneous equations is
A system has poles at 0.01 Hz, 1 Hz and 80 Hz, zeros at 5 Hz, 100 Hz, and 200 Hz. The approximate phase of the system response at 20 Hz is
The value of ultimate period of oscillation \(P_u\) is 3 minutes, and that of the ultimate controller gain \(K_{cu}\) is 2. What is the correct set of tuning parameters (controller gain \(K_C\), the derivative time constant \(\tau_D\) in minutes, and the integral time constant \(\tau_I\) in minutes) for a PID controller using Zielger-Nichols controller settings?

Given the process transfer function \[ G_P = \frac{20}{s - 2}, \] and controller transfer function \[ G_C = K_C, \] and assuming the transfer function of all other elements in the control loop are unity, what is the range of \( K_C \) for which the closed-loop response will be stable?

Given the process transfer function \[ G_P = \frac{4}{(\tau s + 1)^2} \] and the disturbance transfer function \[ G_d = \frac{2}{(\tau s + 1)}, \] what is the correct transfer function for the Feed Forward Controller for perfect disturbance rejection? 

Given the characteristic equation below, what is the number of roots which will be located to the right of the imaginary axis? \[ s^4 + 5s^3 - s^2 - 17s + 12 = 0 \]

The block diagram for a control system is shown below: for a unit step change in the set point, \( R(s) \), the steady-state offset in the output \( Y(s) \) is 

The characteristic equation of a closed-loop system using a proportional controller with gain \(K_C\) is \( 12s^3 + 19s^2 + 8s + 1 + K_C = 0 \). At the onset of instability, the value of \( K_C \) is —————.
A spherical naphthalene ball of 2 mm diameter is subliming very slowly in stagnant air at 25°(C) The change in the size of the ball during the sublimation can be neglecte(D) The diffusivity of naphthalene in air at 25°C is \(1.1 \times 10^{-6} \, m^2/s\). The value of mass transfer coefficient is \( B \times 10^{-3} \, m/s \), where \( B \) (up to one decimal place) is —————.

A mixture of toluene (40%) and benzene (60%) is fed to the distillation column; recovery of benzene is 20% at the top. What is the ratio of the flow rate of benzene from Distillate to the bottoms? (Based on 1000 Kg of feed)?

In a triple-effect backward feed evaporator, the pressure of vapor space in each of the effects is related by —————.
(Hint: Use steam entry as the first effect) 

Kirkbride equation is used for determining the —————.
Which of the following happens in the use of Raschig rings in place of crushed stones as packing in packed beds (other things being same)?
A chemical having specific heat of 3.3 kJ/kg K flowing at the rate of 20000 kg/h enters a parallel flow heat exchanger at 120°(C) The flow rate of cooling water is 50000 kg/h with an inlet temperature of 20°(C) The overall heat transfer coefficient is 1050 W/m\(^2\)K. The heat transfer area is 10 m\(^2\). Take for water, specific heat = 4.186 kJ/kgK. Effectiveness of the heat exchanger will be —————.
The Sun’s surface at 5800 K emits radiation at a wavelength of 0.5 \(\mu m\). A furnace at 300°C will emit through a small opening, radiation at a wavelength of nearly —————.
In a furnace, the wall thickness is 60 cm and is 100 cm wide by 150 cm height, made of material with thermal conductivity 0.4 W/mK. The temperature inside and outside are 1000°C and 4°C, respectively. The thermal resistance is —————.

In a completely opaque medium, if 50 percent of the incident monochromatic radiation is absorbed, which of the following statements are CORRECT? 
- (P) 50 percent of the incident radiation is reflected 
- (Q) 25 percent of the incident radiation is reflected 
- (R) 25 percent of the incident radiation is transmitted 
- (S) No incident radiation is transmitted

For true counter-current flow in a shell and tube heat exchanger, the value of correction factor \( F_T \) is —————.