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Monday, July 24, 2017

Chemical Engineering(Ph.D) 2017

Chemical Engineering(Ph.D)      (1077)

1.      The value of the momentum correction factor for the viscous flow through a circular pipe is 
A)    1.33                 B) 1.50                        C) 2.0                          D) 1.25

2.      A Newtonian liquid (ρ = density, µ = viscosity) is flowing with velocity ν in a tube of diameter D. let ∆ P be the pressure drop across the length L. For a laminar flow, ∆ P is proportional to

A)    L ρν2/D            B)  D ρν2/L                C) Lµν/D2                   D)  µν/L 3. Prandtl number is the ratio of :
A)    Mass diffusivity to thermal diffusivity.
B)     Thermal diffusivity  to Momentum diffusivity 
C)     Thermal diffusivity to mass diffusivity.
D)    Momentum diffusivity to Thermal diffusivity
4.      The ratio of wall drag to total drag in Stokes’s law range is
A)               1                     B) 2/3                           C)  1/3                         D) 4/3

5.      Weight of 56 litres of ammonia at N.T.P. is 
A)               12.5 gms          B) 42.5 gms                 C) 375.5 gms  D) 2500.5 gms

6.      Diffusion coefficient in a binary gas mixture at low pressure varies with pressure as         A) P                      B) P2                                 C) 1/P                          D) independent of P

7.      Cp- specific heat of a gas at constant pressure, at critical temperature and pressure:
A)               Reaches zero                                       B) Reaches 0.34 kcal/ kmol. K
     C) Reaches infinity                                    D) Reaches 1 kcal/kmol. K

8.      For reversible isobaric process the exponent n in   relation  PV n = constant,   has the    
A)               1                      B) 0                             C) ∞                D) 444.4

9.      Jigging is a technique by which different particles can be 
A)               Separated by particle size                   B) Separated by particle density         C) Sepaprated by particle shape   D) Mixed

10.  The dew point of a saturated gas phase is equal to 
A)               Gas temperature                                  B) 0oC
C)  0oC                                                      D) Bubble temperature

11.  At the inversion point , the joule Thomson coefficient is 
A)               Positive           B) Negative                 C) Zero           D) Infinity  
12.  Leiden frost point is concerned with A) Boiling of liquid on hot surface
B)    Condensation of vapour on cold surface
C)    Concentration of solution by evaporation
D)    None of these

13.  A system is said to be isopiestic, if there is no
A)               Temperature change                B) Pressure change
C)  Volume change                                   D) None of the above

14.  On a Mollier chart, the slope of the curve representing a reversible isothermal process is equal to
A)               T – 1/β B) T + 1/β                   C) T – β                      D) T + β
15.  In natural convection  heat transfer  the correlation paprameter is
     A)  Grashof number           
B) Eckert number      
     C)  Graetz  number                         

16. Hardest material of the following is :
D) Bond number

     A) Calcite               B) Quartz      
17. 200 mesh sieve size corresponds to 
C) Corundum    
D) Gypsum
     A) 200 microns    B) 154 microns   
C) 74  microns   
D) 24 microns 

18.  De-sorption of the adsorbed solute by solvent is called
A)    Reverse osmosis                                  B)  Sublimation  
C)  Dialysis                                               D) Elusion

19.  For an open transfer function  G= k /  [ (s+1).(s+2).(s+3) ]   ,  the number of poles are :
A)    Zero                 B) One            C) Two                        D) Three     

20.  Transfer function of a transportation lag is equal to
A)    ____1_____                                         
        τs +1             B)  e-τs                                 C)  eτs                          D) (τs +1)
21.  Working principle of filament type optical  pyrometer is based on the 
A)    Wien’s Law                                         B) Seeback effect             C) Kirchoff’s law                                       D) Peltier effect

22.  Wax is
A)    Mixture of glycerides
B)    A mixture of esters of polyhydric alcohols except glycerin
C)    Liquid at room temp.
D)    Mixture of glycerides

23.  Styrene  butadiene rubber is commercially manufactured by
A)    Bulk polymerization                            B) Suspension polymerization     C) Solution polymerization                        D) Emulsion polymerization

24.  The work done in non-flow reversible process is given by
A)    - Vdp           B)    pdV                  C)   Vdp                   D)    VP
25.  For irreversible elementary reaction in parallel
           K1            K2
         A            R;      A           S

            the rate of disappearance of reactant A is given by
A) (K1-K2) CA        B)  (K1+K2) CA               C) K1 CA                            D) K2 CA
26.    For an ideal plug flow reactor the value of the peclet number is 
A)                ∞                     B)  0                            C)1                              D) 10

27.    In a mixture of benzene vapor and nitrogen gas  at a total pressure of 900 mm Hg. If the absolute humidity of the benzene is 0.2 Kg benzene/ Kg nitrogen, the partial pressure of benzene in mm Hg is 
A)                180                  B) 60.3            C) 720                         D)  200

28.    Which of the following is almost absent in crude petroleum 
A)                Olefins            B) Mercaptans C) Naphthenes            D) Cycloparaffins
29.    The Triple point of water occurs at 0.00602 atm and    
A)                100.01  oC       B) 10.01 oC                 C) 0.01 oC                   D) 0.0001 oC           

30.    The two specific heats Cp and Cv are equal at
A)                0oC                  B) 0oK                         C) 0oF                          D) 0oR

31.    Efficiency of a Carnot  Engine working between hot reservoir at temperature T1 and sink reservoir at temperature T2 is
A)                (T- T2 ) / T1                                  B) (T- T2 ) / T2
C)  T1 / (T- T2 )                           D) T2 / (T- T2

32.    Pure carbon is burnt in oxygen. The flue gas analysis is 70% CO2, 20% CO and 10% O2.
The percent excess oxygen used is 
A)                20                    B) 12.5                        C) 0                             D) 10
33.    The rate constant  of a chemical reaction increases by 100 times when the temperature is increased  from 400  K to 500 K. Assuming transition state theory is valid, the value of E/R is 
A)                8987 K            B)  8764  K                 C) 9210 K                   D) 8621 K 34. Refrigerant Freon-22 is chemically : A) Mono chlorodifluoro methane
B)                Di chlorodifluoro methane
C)                tri chloro mono fluoro methane
D)                tri chloro di fluoro methane 35. In a reversible process: A) TdS = dE + dW
B)    TdS = dE – dW
C)    TdS = dW – dE
D)    TdS = dE

36.  Air at 30oC blows over a plate of 50 cm x 75 cm maintained at  260oC. If the convection heat transfer coefficient  is 25 W/m2.oC, the heat transfer rate is :

A)                2.156 kW        B) 21.56 kW  C) 215.6 kW  D) 2156 kW

37.  A rectangular slab has a surface area of 1.0 m2 and is 4 cm thick. It transmits 10 cal/sec.cm2 due to a temperature difference between its end  faces . If the coefficient of thermal conductivity is 0.8 cal/sec0C and the cooler end is at room temperature 200C What is the temperature of the other face 

A)                30oC                B) 60oC                       C) 70oC                       D) 80oC

38.  In underdamped second order response  overshoot is equal to
A)                (Decay ratio)1/2                                                B) (Decay ratio)1
C)  (Decay ratio)2                                  D) (Decay ratio)3

39.  Solenoid valve works like:
A)                P-D controller                                     B) P-I-D controller
C)  On-off controller                                 D) Proportional controller   

40.  The conversion XA and residence time data are collected for zero order liquid phase reaction in a    stirred tank reactor. Which of the following will be a straight line 
A)                XA versus τ        B)  XA versus  ln τ                C)  XA/ (1- XA)  versus τ               D)  XA* (1- XA)  versus τ

41.  For the gaseous reaction  2A   B, where the feed consists of 50 mol%A and 50 mol% inerts, the expansion factor  is 
       A) 1                    B)  -0.5                          C) -0.25                     D)  0

42.  The root locus method , a pole of transfer function G(s) is the value of s for which G(s) approaches 
       A)  -1                  B) 0                               C) 1                             D) ∞
43.  An evaporator while concentrating an aqueous solution from 10 to 40%, solids evaporates 30,000 Kg of water. The amount of solids handled by the steam  in Kgs are
A)                4000                B)  9000                      C) 4600                       D) 3000

44.  When a multistage tray tower uses  a minimum reflux ratio it implies
A)                Infinite trays  and maximum reboiler heat load
B)                Infinite trays and minimum reboiler heat load
C)                Minimum  trays and minimum reboiler heat load
D)                Minimum  trays and maximum  reboiler heat load

45.  F or absorbing a sparingly soluble gas in a liquid 
A)                Gas side mass transfer coefficient should be increased
B)                Liquid side mass transfer coefficient should be increased
C)                Liquid side mass transfer coefficient should be decreased      D) Mass transfer coefficient must be kept  consistent

46.  The theoretical  minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mol% each of n- heptane and n – octane,  into pure compounds each at 1 atm  is  
A)                - 2 RT ln 0.5                                        B)– RT ln 0.5   
      C)    0.5 RT                                               D) 2 RT
47.  Fluidized beds are formed when
A)                Gravity force is  less than fluid friction 
B)                Fluid friction is  zero
C)                Pressure forces equal gravity forces
D)                Sum of  fluid friction  and pressure forces is equal and opposite to gravity forces
48.  A  counter flow heat exchanger is used to heat water from  200C to 80 0C by using hot exhaust gas entering at 1400C and leaving at 800C. The log mean temperature difference for the heat exchanger is

A)                80 0C               B) 60 0C                      C) 110 0C                    D)  None of the above

49.  An investment of Rs 100 lakhs is to be made for construction of plant which will take two years to start production. The annual profit from operation of the plant is Rs 20 lakhs. What will be the payback time 

A)                5 years             B) 7 years                    C) 12  years                 D) 10 years

50.  For a first order chemical reaction in a porous catalyst, the thiele modulus is 10. The effectiveness factor is approximately equal to

A)                1                      B) 0.1                          C) 0.15                        D) 0


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