- The higher wattage lamp draws more current because, for a constant voltage, a higher power results in a higher current. Using Ohm's Law and the power formula, we have:
I=VP
I=VP
- If the load is removed from the circuit, the current in the circuit would be zero:
I=0
- Differences between measured and calculated resistance values can be due to temperature effects, measurement accuracy, and changes in the lamp filament's resistance when heated:
Temperature effects, measurement accuracy, and filament resistance changes