Un calentador eléctrico trae marcado los siguientes datos 450 watts y 180 Volt. El calentador se conecta a un generador de resistencia interna de 1,2 ohm, la intensidad de la corriente es de 2,1 Amp. Calcular: a) fuerza electromotriz b) Cantidad de calor desprendido en media hora c) Energía eléctrica consumida en un mes, si trabaja 7 horas diarias. d) Diferencia de potencial a los extremos del circuito?

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.