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20°C water is flowing inside a Pyrex tube. A thin electrical heater bonded to the outer surface of the tube is being used to heat the water. The inside and

outside diameters of the tube are 50 mm and 60 mm, respectively. The Pyrex tube and heater are covered with a 10-mm thick layer of glass fiber pipe insulation. The power input to the heater is 1500 W per meter of tube length. The convection heat transfer coefficient for the water flowing in the tube is hy =1800 W/m² . K. The surface of the insulation is= 12 W/m2 · K. Assume k, = 1.3 W/m · K for the exposed to air at T =-5°C with h,Pyrex and k, = 0.034 W/m K for the glass fiber pipe insulation.A a) Find the temperature of the heater (answer: 57.8°C). b) Find the rate of heat transfer to the water in the tube (answer:- 1460 W/m ).

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