(a) Design a band-pass filter consisting of an RC high-pass filter with a cutoff frequency of 125 Hz and an RC low-pass filter with a cutoff frequency of 500 Hz. "Carefully select the R and C of each filter so that one filter does not load the other, changing the cutoff frequencies. Make one" of the two resistors equal to 1.5 kΩ. (b) Sketch and label the circuit. (c) Calculate the gain of the band-pass filter at 125 Hz, 250 Hz, and 500 Hz. (d) Comment on your results in c.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.