Multiple choice question for engineering
1. Flooding, frothing, entrainment are the three main phenomena limiting the tray capacity.
Answer: a [Reason:] A tray has three zones that functions i.e. the active area, the vapor space and the down comer area, these three phenomena can disturb all three places respectively.
2. The flow of vapor liquid in the same direction is defined as?
a) Dual flo
c) Comer flo
d) Coal flo
Answer: b [Reason:] The Jaeger co-flo is based on the novel idea, the vapor flows through the tray deck and carries the liquid droplets to a coalescer placed between two plates.
3. Bubble columns, are used for?
a) Waste water treatment
b) Effluent treatment
c) Chlorine treatment
d) Sodium treatment
Answer: a [Reason:] The main use of bubble column are the aerobic fermenters and are secondarily used a waste water treatment while for chlorine and sodium treatment are done in an agitated vessel.
4. For liquid and solid handling, that are corrosive the
a) Bubble tower is used
b) Venturi Scrubber is used
c) Spray tower is used
d) Agitated vessel are used
Answer: c [Reason:] Spray towers are generally used for the corrosive liquid and gases whereas it also provides the application in the liquid-liquid extraction.
5. The Venturi Scrubber operates on velocity as high as?
a) 250 ft/s
b) 100 ft/s
c) 200 ft/s
d) 150 ft/s
Answer: a [Reason:] The gas is accelerated to a very high speed of 250 ft/s, the high speed gas atomizes the feed liquid causing impaction of dust particles.
6. The shells are generally made of?
Answer: d [Reason:] The ceramic shells are generally used that to having a bell and spigot joint are used in highly corrosive services, such as HNO3 by distillation.
7. Which of the following is the oldest type of the tower packing?
b) Raschig rings
Answer: b [Reason:] This is the oldest type of the tower packing introduced by the German chemist F. Raschig in 1907, it is a hollow cylinder having equal diameter to its length.
8. The modern packing, that is most commonly used in the columns are?
a) Norton Hy-Pak
c) Berl Saddle
d) Pall ring
Answer: c [Reason:] The Berl saddle is first modern packing developed in the late 1930s, it is called so because of its shape of saddle.
9. The carbon steel has the wall thickness and void age of?
a) ½ inch and 92%
b) 1/8 inch and 74%
c) 2/3 inch and 70%
d) ¼ inch and 50%
Answer: a [Reason:] The carbon steel packing’s have ½ inch and 92% void age whereas the Raschig rings have 1/8 inch diameter and 74% void age available.
10. Mellapak structured packing’s have a crimp angle of?
a) 45 or 60o
c) Sharp angle
Answer: a [Reason:] The Mellapak has the crimp angle of 45 or 60o whereas the Flexipak packing has an angle of 45o AND Gempak has the sinusoidal angle and Montz has a very sharp angle of crimp.
1. Tray efficiency correspondingly depends upon?
a) Column Diameter
b) Column throughput
c) Column length
d) Column feed
Answer: b [Reason:] Tray efficiency depends upon column throughput and velocity depends upon the Column Diameter.
2. When a minor fraction of liquid flows to the tray below through the tray perforations it is called
Answer: a [Reason:] During weeping, a minor fraction of liquid flows to the tray below through the tray perforations.
3. When distillate contains highest possibility of light key, D/F approaches
Answer: c [Reason:] When distillate contains highest possibility of light key D/F approaches Unity and lowest when D/F approaches Zero.
4. At higher recovery _____ distillate is produced.
Answer: b [Reason:] At higher recovery ¬¬¬¬More distillate is produced but of lower purity. At a lower recovery the relation follows an inverse character.
5. The vertical D/F line indicated the
a) Maximum impurity level
b) Minimum impurity level
c) More separation
d) Less separation
Answer: a [Reason:] The vertical D/F line indicated the Maximum impurity level at that point on the curve, and this should has to be minimized for better operations.
6. The material balance optimization is also referred as
a) L V optimization
b) B D optimization
c) D B optimization
d) V L optimization
Answer: c [Reason:] D B is optimization at a fixed recovery and L V optimization is done for the matching of feed rates.
7. Raising the column pressure, results in
a) Lower relative volatility
b) Higher relative volatility
c) No effect
d) Higher boiling point
Answer: a [Reason:] The unfavorable effects of raising column pressure is that it lowers relative volatility and thus discarding the products formation.
8. What does DCF represents?
a) Distillation Corp Factor
b) Damping Correction Factor
c) Down Comer Flow
d) Discounted Cash flow
Answer: d [Reason:] DCF is used for estimating payout period, while down comer flow is a physical quantity of column.
9. What does RVP Stands For?
a) Reid Vapor pressure
b) Reflux vapor pressure
c) Reid Viscous Parameter
d) Right Vary Parameter
Answer: a [Reason:] It is a physical property representing Reid Vapor pressure, while for performing reflux operations the Reflux vapor pressure is considered.
10. Energy balance optimization is a prime factor for setting
Answer: b [Reason:] Unlike Material balance optimization, Energy balance optimization can be used for the setting of a distillation column.
1. In matrix language, The Newton Raphson equation is
a) Ji Yif = -Fk
b) Ji Xif = -Fk
c) Ji Kif = -Fk
d) Ji Tif = -Fk
Answer: b [Reason:] In matrix language, The Newton Raphson equation is Ji Xif = -Fk,, here i represents the number of gas rows and j similarly columns of liquid.
2. What is Fk?
Answer: d [Reason:] As Fk= (f1 f2 f3 ……fn)T, Fk is Vector , Matrix and Factor are correlated by an empirical correlation of total functions and temperature.
3. A square nXn matrix is called
a) Jacobin Matrix
b) Raphson Matrix
c) Newton Matrix
d) 2N Matrix
Answer: a [Reason:] A square n X n matrix is called Jacobin Matrix, where the number of row properties are equal to number of column properties.
4. For any instance, XK+1 is
a) Xk + h
b) Xk + t
c) Xk + X
d) Xk + X1
Answer: a [Reason:] For any instance XK+1 is Xk + h, where h is the common difference and Xk is the previous calculated value of series.
5. Independent variable are in the range of
a) Tmin< Tj > Tmax
b) Tmin> Tj > Tmax
c) Tmin< Tj > Tmax
d) Tj < Tmax
Answer: c [Reason:] Independent variable are in the range of Tmin < Tj < Tmax, i.e. the maximum temperature should be less than initial and greater than the final temperature.
6. In quasi Newton Method, Sk represents the
a) Vector factor
b) Scalar factor
c) Separation factor
d) Correction factor
Answer: b [Reason:] In quasi Newton Method, Sk represents the Scalar factor, while function quantiles such as temperature and pressure relations are called as vector ones.
7. Solve cos x = 2x?
Answer: c [Reason:] Solving f(x) = 0 then f(x) = cos x − 2x, x0 = 0.5, x1 = 0.45063, x2 = 0.45018, x3 = 0.45018, the root is x = 0.45018.
8. Find XK+1? If Xk = 0.5, consider a difference of 5 stages
d) Can’t be calculated
Answer: b [Reason:] For XK+1 = Xk + h = 0.5+ 5 = 5.5.
9. The first assumption of the NR Method is
a) Assume K=0
b) Assume Xi = 0
c) Assume F(x) = 0
d) Assume F’(x) = 0
Answer: a [Reason:] The first assumption of the NR Method is assume K=0, as we assume k=0, then we calculate F(x) = 0 and then F’(x) = 0.
10. Jacobin equation is solved using the
a) Matrix Multiplication
b) LU Factorization
c) Elimination Method
d) Follow up method
Answer: b [Reason:] Jacobin equation is solved using the LU Factorization method, where we eliminate the lower and upper triangle matrix resulting in a singular matrix.
1. Fenske’s Equation can be written as
a) Nmin = S/ ln α
b) Nmin = ln S/ ln α
c) Nmin – 1 = ln S/ ln α
d) Nmin + 1 = ln S/ ln α
Answer: b [Reason:] The Fenske’s equation is given by this equation Nmin = ln S/ ln α, where N is the number of trays and alpha is the relative volatility.
2. The term S in the Fenske’s equation, is given as
Answer: a [Reason:] The term S in the Fenske’s equation is given as (xLKxHK)D(xLKxHK)B, representing High and Low keys of the gas and liquid phases.
3. N√αN this equation is called as
a) Sorel’s Method
b) Polson Equation
c) Fenske’s Equation
d) Gilliland Equation
Answer: c [Reason:] Fenske’s Equation that is rigorous, Gilliland Equation are used and based on the trial and error basis.
4. Calculate ln S? If XLK=0.41 and XHK = 0.005 and XL= 0.417 and XH= 0.01, then
Answer: c [Reason:] As ln (0.41/0.005) (0.417/0.01) = 8.137.
5. A non-key component may be distributed if
a) Close to that of one key
b) The Specified separation is sloppy
c) Intermediate between keys
d) Intermediate one key
Answer: b [Reason:] For distributed systems the Specified separation is sloppy, while for the distributed system it is close to that of one key.
6. In a distillation operation, the reflux ratio may vary between
a) Zero and one
b) Zero and infinity
c) Minimum and infinity
d) One and two
Answer: a [Reason:] L0/D Varies from zero to one, as the ratio cannot be more than one because that will cause the failure of the column.
7. Most distillation columns are designed for reflux ratio between
a) 3 to 5 Rmin
b) 1.2 and 1 .7 Rmin
c) 2 to 10 Rmin
d) 0.2 to 0.7 Rmin
Answer: b [Reason:] This is the most suitable for 1.2 and 1.7 Rmin times reflux ratio, this also reduces the operating and the final cost of the system.
8. If Component is non-distributed, then
a) DR >1
Answer: a [Reason:] If component is non-distributed then DR >1 contained entirely distillate, while if components are distributed they are entirely withdrawn.
9. If Component is distributed, then
a) 0< DR> 1
b) 0< DR< 1
c) DR= 0
d) DR < 0
Answer: b [Reason:] If Component is distributed then 0< DR< 1, DR is recovery component, if DR = 0 then there exists no distributed components in the systems.
10. Underwood’s equation can be used to find
a) Distributed components
b) Non distributed components
c) Reflux for components
d) Non reflux components
Answer: a [Reason:] Underwood’s equation can be used to find Distributed components (n) including key.
1. Relaxation methods were developed for solving?
a) Co linear systems
b) Sub linear systems
c) Linear systems
d) Bilateral systems
Answer: c [Reason:] Relaxation methods were developed for solving linear systems, similar as matrix systems the relaxation method can be used to find values of unknowns.
2. The below equation follows?
a) Change in Temperature
b) Change in Time
c) Change of T Stages
d) Change of X Stages
Answer: a [Reason:] The above equation follows Change in Temperature in Euler’s form, where Tj,k+1 is the calculated temperature conforming liquid temperature.
3. The next trail, for the below equation is
Answer: b [Reason:] The Euler’s equation is next trail K+1, where Xij,k+1 is the calculated feed stream of liquid using the initial feed conditions.
4. The below curve is called as the
a) Homologues Curve
b) Homotomy Curve
c) Euler’s Curve
d) Newton Curve
Answer: b [Reason:] The following curve is called as the Homotomy path, as the function rises from G(x)
That is simpler one to F(x) the complex one.
The below equation is for question 5 and question 6.
5. F(x) stands for
a) Simpler solution
b) Complex Solution
c) Difficult Solution
d) Simple Solution
Answer: c [Reason:] F(x) stands for Difficult Solution, as we can follow the Homotomy equation curve and path of curve.
6. G(x) stands for
a) Simpler solution
b) Complex Solution
c) Difficult Solution
d) Simple Solution
Answer: a [Reason:] G(x) stands for simpler solution, starts with an initial value the G(x) is the Homotomy parameter representing simpler set of solution.
7. The Homotomy parameter, t travels between
a) 0 and 1
b) 0 and infinity
c) 1 and infinity
d) 1 and -1
Answer: a [Reason:] The Homotomy parameter “t” travels between 0 and 1 from G(x) to F(x), accordingly it is the varying factor of relation between G(x) and F(x).
8. The solution is converged when
a) F(x) =0
b) G(x) =0
c) G’(x) =0
d) F’(x) =0
Answer: a [Reason:] The solution is converged when F(x) =0 so that t=1 and H(x,t)=0, this is proved numerically and cannot be changed.
9. LU decomposition is used when
a) Ax (k) = Y (k)
b) Ax (k) = bX (k)
c) Ax (k) ≠ b (k)
d) Ax (k) = b (k)
Answer: d [Reason:] LU decomposition is used when Ax (k) = b (k) is to be solved for several different values of vector b.
10. The below equation is?
a) Poisons’ Equations
b) Euler’s Equation
c) Newton Equation
d) Crab Equation
Answer: b [Reason:] The above equation is an Euler’s Equation, as it consists of the differential term and the nth value of x feed stream.