Which of the following statements about intersystem bonding is correct? a. Intersystem bonding is required at the service equipment but is optional at buildings supplied by a feeder.
b. Intersystem bonding is optional at the service equipment but is required at buildings supplied by a feeder.
c. Intersystem bonding is required at the service equipment and at buildings supplied by a feeder as well.
d. Intersystem bonding is required at the main distribution for mobile home parks but is not required at the disconnecting means at the mobile home.

Aflywheel accelerates for 5 seconds at 2 rad/s2 from a speed of 20 rpm. determine the total number of revolutions of the flywheel during the period of its acceleration. a.5.65 b.8.43 c. 723 d.6.86

Agas mixture consists of 8 kmol of h2 and 2 kmol of n2. determine the mass of each gas and the apparent gas constant of the mixture.

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.