Answer / kangchuentat

ELECTRICAL TECHNOLOGY - ANSWER 16.3 : (a) Input = Output / Efficiency = 100 watts / 0.5 = 200 watts. (b) Number of inverter = Input / Rated power = 200 / 300 = 2 / 3 < 1. Practically only 1 inverter is needed. (c) I = Pin / V = 200 / 12 = 16.667 A. (d) Number of charge controllers = Input / Rated current = 16.667 / 10 = 1.6667 < 2. Practically only 2 are needed. (e) Energy consumption = 0.1 kilowatt x 2 hours / day = 0.2 kilowatt hour per day. (f) Input energy = Energy consumption / Efficiency = 0.2 / 0.5 = 0.4 kilowatt hour per day. (g) Energy generation per day per solar panel = 2.88 hours x 0.02 kilowatt = 0.0576 kilowatt hour. (h) Number of solar panels needed = Answer for (f) / Answer for (g) = 0.4 / 0.0576 = 6.944 < 7. Practically only 7 are needed. (i) Ampere hour per day to run the load = 0.4 kilowatt hour per day / 12 V = 1 / 30 k. Total ampere hour needed for 3 days = 1 / 30 k x 3 = 0.1 k. Number of batteries needed = 0.1 k / 5 = 100 / 5 = 20. The answer is given by Kang Chuen Tat; PO Box 6263, Dandenong, Victoria VIC 3175, Australia; SMS +61405421706; chuentat@hotmail.com; http://kangchuentat.wordpress.com.

MICROBIOLOGICAL ENGINEERING - QUESTION 28.2 : A hemocytometer is a device that is used for counting cells. In an engineering experiment, 100 microlitres of cell suspension is diluted with 50 microlitres of Trypan blue dye. Only death cells appear blue in color when stained with the dye. There are 57 cells detected in a hemocytometer, where 5.3 % of them appear blue when the chamber of the meter is placed under a microscope. Each square of a chamber can contain 0.0001 mL of liquid. (a) Calculate the number of viable cells. (b) The cells occupied 5 squares. Calculate the average number of viable cells / square. (c) Calculate the dilution factor of the cell suspension by using the formula : Dilution = final volume / initial volume. (d) Calculate the concentration of viable cells / mL by using the formula : Concentration = (Average number of viable cells / square) x dilution x (square / volume).

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ELECTRICAL TECHNOLOGY - EXAMPLE 16.1 : 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.

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Why are decomposition reactions called the opposite of combination reactions?

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how to convert Nm3/hr to Kg/hr for air, @ 10.4 kg/cm2.g dischare pressure, does density doesn't affect on calculation?

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Question 87 - According to Hardy-Weinberg Equation, p x p + 2 x p x q + q x q = 1 where p = dominant allele frequency and q = recessive allele frequency. Let p + q = 1. Fraction of population has 2 copies of the p gene = p x p. Fraction of population has 2 copies of the q gene = q x q. Fraction of population has a copy of p gene and a copy of q gene = 2 x p x q. In a small town, the allele frequency is q = 0.2 for a recessive gene, the delta-32 mutation, that gives human protection from HIV infection. (a) Find the allele frequency a dominant gene, p. (b) What percent of the population has at least a copy of the gene that cause the population either immune to HIV or less susceptible to the disease?

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Question 77 - The molecular weights M in kg / mol of 3 different monomers a, b and c in a polymer are Ma = 14, Mb = 16 and Mc = 18, with their respective quantities in N units having the ratio of Na : Nb : Nc = 2 : 3 : 5. (a) Find the numerical average molecular weight of the polymer by using the formula (Ma Na + Mb Nb + Mc Nc) / (Na + Nb + Nc). (b) Find the weighted average molecular weight of the polymer by using the formula (Ma Na Ma + Mb Nb Mb + Mc Nc Mc) / (Ma Na + Mb Nb + Mc Nc). (c) Calculate the polydispersity Q by using the answer in (b) divided by answer in (a). (d) Find the volumetric average molecular weight of the polymer by using the formula (Ma Na Ma Ma + Mb Nb Mb Mb + Mc Nc Mc Mc) / (Ma Na Ma + Mb Nb Mb + Mc Nc Mc). (e) Estimate the polydispersity Q by using the answer in (d) divided by answer in (b).

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Name some factors to consider when trying choosing between a dry screw compressor and an oil-flooded screw compressor?

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why Torispherical heads are used in pressure vessels?

1 Answers   India Cements,

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what is the difference between the heat exchanger and cooling tower???????????

10 Answers   BARC, Essar,

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Are there any special considerations to be taken into account for combustion ammonia?

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How can you estimate the efficiency of a pump?

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from which book shud i will prepare for the hpcl and various company exma i m fresher and my basic is not strong could u suggest from where to start

7 Answers   IOCL,

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