Which of the following statements are true? check all that apply. check all that apply. the potential difference between the terminals of a battery, when no current flows to an external circuit, is referred to as the terminal voltage. a battery is a device that produces electricity by transforming chemical energy into electrical energy. the internal resistance of a battery decreases with decreasing temperature. a battery does work on electric charges to bring them to a position of higher electric potential energy so that they can flow through a circuit to a lower potential energy.

The filament of an incandescent lamp has a temperature of 2000k. calculate the fraction of radiation emitted in the visible light band if the filament is approximated as blackbody

Slip occurs via two partial dislocations because of (a) the shorter path of the partial dislocation lines; (b) the lower energy state through partial dislocations; (c) the charge balance.

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.