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(1) Lewis number, Le is given by |
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(a) Sc /Pr |
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(b) Re.Pr |
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(c) Sc.Pr |
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(d) Sh.Pr |
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(2) Absorption factor is defined as |
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(a) mGL |
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(b) mG/L |
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(c) G/mL |
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(d) L/mG |
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(3) A particle attains its terminal velocity when |
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(a) gravity force + drag force=buoyancy force |
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(b) gravity force - drag force=buoyancy force |
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(c) buoyancy force = gravity force |
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(d) drag force=buoyancy force |
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(4) In common fluids flowing through tubes, heat transfer by conduction is limited to the viscous sub layer. In liquid metals flowing through tubes, |
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(a) likewise, heat transfer by conduction is limited to the viscous sub layer |
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(b) heat transfer by conduction is important in the viscous sub layer as well as in the buffer layer |
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(c) heat transfer by conduction is important throughout the entire turbulent core |
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(d) Heat transfer by convection only is important; heat transfer by conduction is negligible even in the viscous sub layer |
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(5) Under otherwise uniform conditions Fanning friction factor for a rough pipe is |
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(a) smaller than that for a smooth pipe |
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(b) greater than that for a smooth pipe |
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(c) equal to that for a smooth pipe. |
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(6) A hot fluid at 100oC is to be cooled to 60oC in a double-pipe heat exchanger by using a coolant which will be heated from 30oC to 60oC. If the hot and cold streams flow concurrently, the driving force for heat transfer (by mean temperature difference) is equal to |
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(a) 0 oC |
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(b) 30oC |
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(c) 40oC |
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(d)none of these |
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(7) In SI system, net positive suction head (NPSH) has a unit of |
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(a) kg/ m2 |
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(b) N/ m2 |
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(c) J/ m |
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(d) J/kg |
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(8) Cavitation will not occur if the sum of the velocity and pressure heads at the suction is
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(a) zero |
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(b) much larger than the vapour pressure of the liquid |
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(c) much smaller than the vapour pressure of the liquid |
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(d) Equal to the vapour pressure of the liquid. |
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(9) For a counter-current heat exchanger the clean overall heat transfer coefficient is 500 W/m2.K and the overall fouling factor is 0.00035 m2 K/W. What will be the value of the design overall heat transfer coefficient? |
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(a) 485.6W/m2.k |
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(b) 425.5 W/m2.k |
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(c) 392.8 W/m2.k |
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(d) none of the foregoing. |
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(10) For the situation in q 130, the Thiele modulus will be defined as f equal to |
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(11) A series reaction  is being conducted in a PFR. To maximize the production of R, the optimum space time should be equal to |
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(12)  Between the limits of 0 and µ is equal to |
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(a) 0 |
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(b) 0.1 |
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(c) 1.0 |
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(d) 10 |