Question

Please i need help here, answer the problems with { your explain}.

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1. During which case will the power loss be maximum? a) High viscosity oil b) Low viscosity oil c) High viscosity water d) Low viscosity water View Answer

Answer 1

#1. (a) we know that, head loss due to friction in the pipe causes power loss. Now, head loss is given as, hl= flu2 zgd i laminar flow f = friction factor 0.316 , for turbulent frow, g= 9.81 mis? Relu 1 = length of pipe (m) V = velocity 13/A)./mis) where, &= flow rate (m3/s), = Area of Pipe d = diameter of pipe. ort h2= f LQ? 12d5 Now, of fluid) 1245 power 10ss = s9 8h ---(8= density =398. flg? 7205 = 2 gg²fL = 84 ( 994 ) Hence, ploss & sf also, father and Re di iscosity .: f viscosity). So, 1 Poss 2 S x viscosity

Swater > Soil (almost comparable ) but viscosity of oil >77 viscosity of water .: Poss will be maximum in case of High Viscosity oil. .: so, option cas is correct. #2.16) In rotating Shaft, N= rpm = revolution I min. so, angular speed w= 2TN radls 60 # 3. (C) we know, that, speed V - W x Radius of shaft 1. = wxR = wo (= diameter of shaft) w = 2IN 60 60 ...tv = mon mis! #4.(d) Resistance in fluid is due to Shear Stress in different layers. This shear stress depends on viscosity of fluid. Also, viscosity depends on temperature Pressure and volume. So, It doesnot offer gesistance to shape.