Answer / debshree

ANSWER 1 IS CORRECT

Answer / vinay upadhyay

answer (d) is correct . because here change of tempr is depend on characteristic length of object and according to ques characteristic length of each will same so their gainig of 90% of tempr difference will requires same time . tou =row *characteristic length*heat capacity /heat transfer cofficient

Answer / vas

answer 1 (cube) is correct since temp change depends on few
factors, one of which is footage (S) of contact between the
body and substance. Among other equal factors the footage
is different. Thus, the only problem for us here is to find
out solution how to compare footages of the bodies we have.
Since we know that their weights are equal and know the
formulas for figuring out their weights, we will find soon
that the smallest S belongs to the cube, consequently the
biggest belongs to the sphere.

how to design a heat exchanger?

3 Answers   TATA,

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hai....i am chandrika. if anybody having test questions for HAL,HPCL,ONGC,IOL...PLS SEND THE QUES WITH SOLVED ANSWERS TO ME TO MY MAIL ID chandrismiles@yahoo.co.uk

0 Answers   HAL,

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why rotameter has variable area?? is it necessary??

1 Answers  

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Question 8 - A local utility burns coal having the following composition on a dry basis : Carbon (C) 83.05 %, hydrogen (H) 4.45 %, oxygen (O) 3.36 %, nitrogen (N) 1.08 %, sulfur (S) 0.7 % and ash 7.36 %. Calculate the ash free composition of the coal with reference to C, H, O, N and S.

1 Answers  

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distillation types (vacuum, azeotropic, steam, extractive)

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According to Shockley equation, the I – V characteristic of a diode is approximated by I = IS [ exp (nVD / VT) – 1 ]. For silicon, let the reverse bias saturation current IS as 0.000000000001. If n is ideality factor with value of 1.5, VT as thermal voltage drop of 0.026 V at room temperature, what is the value of current I that passes through the silicon diode in the heater of evaporator when the forward voltage drop VD = 0.026 V? Please take note that exp is the exponential function with e(1) = 2.718, e(2) = 7.389.

1 Answers  

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What diffrence between flush distillation & batch distillation ?

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What are the types of membranes used in RO water treatement plant?

2 Answers  

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Explain what is the method involved in analyzing powders for composition?

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Question 88 - In the calculation of the growth of bacteria, colony forming unit (CFU) in serial dilution is used. In a laboratory, viable count assay is used to estimate CFU. Formula applied is CFU / mL = (number of colonies x dilution) / (amount plated, in unit mL). Acceptable plate count is either between 20 and 200 or between 30 and 300 according to 2 different references. A wastewater sample of 200 ml is added to and mixed with 1.8 L of sterile water. Another 200 ml of the mixture is added to and mixed with 1.8 L of sterile water. (a) Calculate the dilution of first mixture and the dilution of the second mixture. (b) 100 microlitres of wastewater samples from the first mixture and the second mixture are placed separately on 2 different alga plates. The first plate has 250 colonies and the second plate has 23 colonies. Calculate the average CFU / mL.

1 Answers  

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What types of metals are typically removed via chemical precipitation?

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Question 94 - The resolution of separation, Rs for chromatography is given by the formula Rs = (difference in retention time) / (average width at the base). In a chromatogram, 3 peaks a, b and c are found. Average widths W at the bases of the solutes are : Wa = 20 s, Wb = 40 s, Wc = 30 s. Resolutions of separation, Rs for solutes b and c in comparison to a are 2 and 4 respectively. The differences in retention times T for b and c in comparison to a are (Tb - Ta) and (Tc - Ta), Ta = Tc - Tb : (a) Form 2 equations involving Rs as a function of Wa, Wb, Wc, Ta, Tb and Tc. (b) Find the values of Ta, Tb and Tc.

1 Answers  

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