Answer / venkatesh n

nusselt number quantifies how much the convection heat transfer could be higher when compared with the conduction heat transfer, if the fluid were stationary.
biot number provides a way to compare the conduction resistance within a solid body to the convection resistance external to that body (offered by the surrounding fluid) for heat transfer.

Answer / shashank

biot number is used In partial unsteady state heat transfer and it is the ratioof conduction resistance of that body and external convention resistance of fluid.....( means when a solid body is surrounded by a fluid )

where as nussult no corresponds to fluid ie fluid layer which is just near the solid body ( assume pipe ) acts as solid and type of heat transfer is conduction here..... and above this fluid layer convention is taking place....
nussult no is the ratio of this conduction resistance of FLUID to convention t resistance of FLUID....

Answer / chemical engineer

it differs only in characterisic length u take..

Given, T1=600C, constant temperature of wall 800 , length of wit exchanger L=3m, dia=25 mm, Cp=14.91 KJ/kg.K, density ρ=914 kg/m3,mean velocity vm= 2 m/s, film heat transfer coefficient hf=72 Kcal/h.m2.K, what is the outlet temperature?

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Three solid objects of the same material and of equal mass – a sphere, a cylinder (length = diameter) and a cube – are at 5000C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining the bath temperature eventually. The time required for 90% change of temperature is smallest for a) cube b) cylinder c) sphere d) equal for all the three whyyyyyyy???????

3 Answers   GATE,

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Is it ever advantageous to use shells in series even though it may not be necessary?

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Question 61 – A biochemical trolley of mass 15 kg is towing a trailer of mass 5 kg along a straight horizontal pathway. The trailer and the trolley are connected by a light inextensible tow-bar. The engine of the trolley exerts a driving force of magnitude 100 N. The trailer and the trolley experience resistances of magnitude 10 N and 30 N respectively. (a) Form 2 equations with unknowns T and a, that represents the equilibrium for the 2 systems of the trolley and trailer. (b) Solve the simultaneous equations from the 2 equations that are obtained in part (a) of this question. T is the tension of the tow-bar and a is the acceleration.

1 Answers  

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What is difference between overall heat transfer coefficient & individual heat transfer coefficient?

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ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.21 : The cost of building a biochemical processing plant is increasing due to inflation. Let I = inflation rate, R = nominal interest rate, r = real interest rate. According to Fisher Equation, (1 + r)(1 + I) = (1 + R). According to General Inflation Equation, R = r + I. (a) By assuming that both r and I are fairly small, prove by mathematical calculations that complicated Fisher Equation could be simplified into the General Inflation Equation. (b) By using 2 first order Taylor expansions in the linear approximation, namely 1 / (1 + x) ≈ (1 - x), (1 + x)(1 + y) ≈ 1 + x + y, show by mathematical calculations that (1 + r) = (1 + R) / (1 + I) could be approximated by r ≈ R - I.

1 Answers  

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ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.5 : In an American style option for share market, 2 persons - A and B agree to the following : B is required to sell 100 shares of IBMS to A for $85 per share anytime that A wants in the next 8 months. A will pay B $2 per share up front, non-refundable for this option. IBMS involves in petrochemical processing. IBMS stock is currently selling for $80 per share. (a) If A did not buy the share of IBMS from B after 8 months, how much will B earn? (b) If the share of IBMS goes up to $100 / share in 6 months later : (i) how much should A pay B for 100 shares according to their optional agreement? (ii) how much will A earn from 100 shares purchased from B when all the 100 shares are sold to the open market? (iii) how much net profit will A earn for selling 100 shares to the open market?

1 Answers  

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need the type of technical questions in written test

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Explain what are the advantages of using gear pumps?

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What is difference between Piping Standard & Piping Specification ?

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Question 10 - In the US (United States), one barrel is equal to 42 US gallons and equivalent to 0.15898 cubic metres. One British barrel is equal to 36 Imperial gallons and equivalent to 0.163659 cubic metres. If an oil refinery in England sells 42 Imperial gallons of crude oil to a company in US, how much US gallons of crude oils has been sold?

1 Answers  

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plz send me hpcl and reliance entrance test papers on my id s,kumar_bk@yahoo.co.in

1 Answers   Reliance,

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