A3-mm-diameter electrical wire is insulated by a 2-mm-thick rubberized sheath (k = 0.13 w/m ⋅ k), and the wire/sheath interface is characterized by a thermal contact resistance of rt ,c 3 10 m k/w ′′ = × −4 2 ⋅ . the convection heat transfer coefficient at the outer surface of the sheath is 15 w/m2 ⋅ k, and the temperature of the ambient air is 20°c. if the temperature of the insulation may not exceed 50°c, what is the maximum allowable electrical power that may be dissipated per unit length of the conductor? what is the critical radius of the insulation?

Ahouse has the following electrical appliance usage (1) single 40w lamp used for 4 hours per day (2) single 60w fan used for 12 hours per day (3) single 200w refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours find the solar power inverter size in watt with correction factor of 1.25.

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.

Fluids at rest possess no flow energy. a)- true b)- false