Question 100 - (a) Time evolution in Heisenberg picture, according to Ehrenfest theorem is m (d / dt) < r > = < p >, where m = mass, r = position, p = momentum of a particle. If v = velocity, prove that m < v > = < p >. (b) Lande g-factor is given by Gj = Gl [ J (J + 1) - S (S + 1) + L (L + 1) ] / [ 2J (J + 1) ] + Gs [ J (J + 1) + S (S + 1) - L (L + 1) ] / [ 2J (J + 1) ]. If Gl = 1 and under approximation of Gs = 2, prove by calculation that Gj = (3/2) + [ S (S + 1) - L (L + 1) ] / [ 2J (J + 1) ].

1 Answers  

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What is meant by surging in compressors?

5 Answers   CPCL,

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what is unit operation?

8 Answers   Sun Pharma, Zydus Cadila,

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Explain the different ways in which solids can be blended?

0 Answers  

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FOOD ENGINEERING - QUESTION 23.2 : (a) A dryer reduces the moisture content of 100 kg of a potato product from 80 % to 10 % moisture. Find the mass of the water removed in such drying process. (b) During the drying process, the air is cooled from 80 °C to 71 °C in passing through the dryer. If the latent heat of vaporization corresponding to a saturation temperature of 71 °C is 2331 kJ / kg for water, find the heat energy required to evaporate the water only. (c) Assume potato enters at 24 °C, which is also the ambient air temperature, and leaves at the same temperature as the exit air. The specific heat of potato is 3.43 kJ / (kg °C). Find the minimum heat energy required to raise the temperature of the potatoes. (d) 250 kg of steam at 70 kPa gauge is used to heat 49,800 cubic metre of air to 80 °C, and the air is cooled to 71 °C in passing through the dryer. If the latent heat of steam at 70 kPa gauge is 2283 kJ / kg, find the heat energy in steam. (e) Calculate the efficiency of the dryer based heat input and output, in drying air. Use the formula (Ti - To) / (Ti - Ta) where Ti is the inlet (high) air temperature into the dryer, To is the outlet air temperature from the dryer, and Ta is the ambient air temperature.

1 Answers  

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I will complete chemical engg next yr from a deemed university. Earlier I dropped 2 yrs after std 12th. Then I got 2 yr back while completing engg, due to reasons beyond my control. Will I face any problem while applying for job. More so not many core companies come to our collg for placement. So i want to know which all companies can I apply to get a job?

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What is a black body?

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I am writing the chemical engineering subject test for Reliance India Limited. Could someone who has taken the test please list some of the questions from that paper?

2 Answers  

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Explain what types of valves are recommended for slurry services?

0 Answers  

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1.How a chlorine leak is detected? 2.What would happen if excess chlorine is added to water in cooling tower?

3 Answers  

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What type of pump may be appropriate for a liquid near saturation, a low flow rate, and very limited npsha (net positive suction head available)?

0 Answers  

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what is the hearth and arch pressure in furnace?

0 Answers   Essar, TATA,

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