Steam at 200°C flows in a cast iron pipe (k = 80 W/m-°C) whose inner and outer diameters are D, = 0.20 m and D2 = 0.22 m. The pipe is exposed to room air at 30°C. The heat transfer coefficients at the inner and outer surfaces of the pipe are 75 and 30 W/m2.°C, respectively. The pipe is to be covered with 2.6 cm-thickness glass wool insulation (k = 0.05 W/m-°C) to decrease the heat loss from the steam. The percentage decrease in heat loss from the steam due to insulation is . . %. Select one: O a. 95.1 b. 94.0 X O c. 93.2 O d. 92.5 O e. 90.7

Steam at 200°C flows in a cast iron pipe (k = 80 W/m-°C) whose inner and outer diameters are D, = 0.20 m and D2 = 0.22 m. The pipe is exposed to room air at 30°C. The heat transfer coefficients at the inner and outer surfaces of the pipe are 75 and 30 W/m2.°C, respectively. The pipe is to be covered with 2.6 cm-thickness glass wool insulation (k = 0.05 W/m-°C) to decrease the heat loss from the steam. The percentage decrease in heat loss from the steam due to insulation is . . %. Select one: O a. 95.1 b. 94.0 X O c. 93.2 O d. 92.5 O e. 90.7

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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