Physics Practice Problems Power in Circuits Practice Problems Solution: For most materials, the resistance is actually tem...

Solution: For most materials, the resistance is actually temperature dependent, and typically increases as temperature rises. For this problem, however, let's assume a very simple (if not physical) case. A 100 Ω resistor with a mass of 0.15 kg is connected to a 120 V power source. So long as the temperature is below 1000°C, the resistance remains 100 Ω, but once it rises above 1000°C, the resistance immediately becomes infinite, and the circuit can no longer operate. How long could this circuit run? The specific heat of the resistor we are considering is 50 J/g*K and we will assume the resistor begins at room temperature, about 23°C.

Problem

For most materials, the resistance is actually temperature dependent, and typically increases as temperature rises. For this problem, however, let's assume a very simple (if not physical) case. A 100 Ω resistor with a mass of 0.15 kg is connected to a 120 V power source. So long as the temperature is below 1000°C, the resistance remains 100 Ω, but once it rises above 1000°C, the resistance immediately becomes infinite, and the circuit can no longer operate. How long could this circuit run? The specific heat of the resistor we are considering is 50 J/g*K and we will assume the resistor begins at room temperature, about 23°C.