In an electric toaster, electricity passes through thin metal wires (called filaments) inside the toaster, causing the wires to glow and heat up. the heat given off by the filaments then toasts the bread. if 500 kilojoules of electricity are supplied to a toaster, which choice below could represent the total amount of heat energy given off by the filaments of the toaster? a. 505 kilojoules b. 630 kilojoules c. 520 kilojoules d. 480 kilojoules

Asquare isothermal chip is of width w=5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated; the front surface is exposed to the flow of a coolant at tinf=15 °c. from reliability considerations, the chip temperature must not exceed t=85 °c. if the coolant is air and the corresponding convection coefficient is h=200 w/m2 x k, what is the maximum allowable "power" of the chip? if the coolant is a liquid for which h=3000 w/m2 x k, what is the maximum allowable power of the chip?