How does electrical resistance affect the heating element in a toaster?
Resistance is the reason that the element heats up when the toaster is plugged in to an electric power supply. The heating element in a toaster is typically a wire made of a mixture of metals (an alloy) such as nickel and chromium, which has a higher electrical resistance than a copper wire. When the toaster is plugged in and switched on, current flows through the wire. Resistance causes the wire to heat up and glow orange, creating infrared radiation that warms the surface of the bread. The losses in power are called Joule heating or P (joule). Those losses are equal to: P (joule) = RI2 This equation derives from the equations P=VI and V=RI (Ohm’s Law) P is the power (in Watts). R is the resistance of the wire (in Ohms) I is the current though the wire (in Amperes) V is the voltage tension across the wire (in Volts) From the Joule heating equation, you can see that the heat (P) will be high when electrical resistance (R) is high. The current that flows through the wire has a very high
