Vikram Sarabhai Space Centre Scientist/ Engineer Chemical Paper 2015
| 1 | Two iron pipes of the same nominal diameter but different schedule numbers will have
(a) The same inside diameter (b) The same outside diameter (c) The same wall thickness (d) None of the above |
| 2 | Air at room temperature and atmospheric pressure is flowing through a rotameter at a flow rate of 100 cc/s. If Air is replaced by Helium (mol.wt.4) and the rotameter shows the same reading, the flow rate of Helium is
(a) 56 cc/s (b) 42 cc/s (c) 269 cc/s (d) 325 cc/s |
| 3 | A ship whose hull length is 100 m is to travel at 10 m/s. For dynamic similarity, at what velocity should a 1:25 model be towed through water?
(a) 10 m/s (b) 25 m/s (c) 2 m/s (d) 50 m/s |
| 4 | Two engineers are calculating the average molecular weight of a gaseous mixture containing oxygen and other gases. One of them using the correct molecular weight of 32 for oxygen, determines the average molecular weight correctly as 39.2. The other using an incorrect value of 16, determines the average molecular weight as 32.8. This is the only error in his calculations. What is the mole percent of oxygen in the mixture ?
(a) 30 (b) 40 (c) 50 (d) 60 |
| 5 | The rate constant of a chemical reaction increases by 100 times when the temperature is increased from 400 to 500 K. Assuming transition state theory is valid, the value of E/R is
(a) 8764 (b) 9210 (c) 8987 (d) 8621 |
| 6 | For a turbulent flow in a tube, the heat transfer coefficient is obtained from the Dittus-Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer coefficient will change by a factor of
(a) 1.0 (b) 1.74 (c) 7 (d) 37 |
| 7 | A thermic fluid at 150 dgree C is used to heat a cold fluid at 30 degree C in a 1-1 shell and tube heat exchanger. The exit temperature of the themric fluid is 110 dgree C. Find out the overall heat transfer coefficient. Assume the mass flow rates, heat capacities of both the fluids are the same.
(a) 0.5 (b) 0.4 (c) 0.036 (d) 0.36 |
| 8 | In a ball mill of diameter 2000 mm, 100 mm diatmeter steel balls are being used for grinding. Presently for the material being ground, the mill is running at 15 rpm. At what speed will the mill have to run if the 100 mm balls are replaced by 50 mm balls, all other conditions remaining the same?
(a) 31 rpm (b) 15 rpm (c) 62 rpm (d) 25 rpm |
| 9 | A leaf filter filtering slurry, gave a total of 8 cubic meter filtrate in 30 min. Filtration was continued till 11.3 cubic meter of filtrate was collected. Estimate the washing time in minutes if 11.3 cubic meter of wash water is used. The resistance of cloth can be neglected and a constant pressure is used throughout
(a) 110 min (b) 120 min (c) 130 min (d) 140 min |
| 10 | A typical example of a physical system with under damped characteristics is a
(a) U-tube manometer (b) Spring loaded diaphragm valve (c) CSTR with first order reaction (d) Thermocouple immersed |
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