Explain the operation of the alarm system and strobe lighting system: By determining the resistance of the resistor in the alarm circuit and explain the
functionality of the resistor in the circuit;
(ii) By providing all circuit theory explanations and calculations to show that the voltage in
the alarm system can be reduced to 5V since the system needs to operate with a current
between 0.4mA to 0.6mA;
(iii) By providing all charge theory explanations and calculations to show the current flowing
in the strobe lighting system.
Without calculating the values oynlain how the current

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.