🔍 Key Concepts

• Ohm's Law (relationship between voltage, current, and resistance) • How to calculate the current drawn by the lamp from its power and voltage rating • Effect of internal resistance of the battery on the total circuit resistance

💭 Think About

• First, from the lamp’s voltage and power ratings, what current does the lamp itself draw under ideal conditions? • Once you know the lamp current, what is the corresponding resistance of the lamp? • When you connect the lamp to the battery, how do you combine the lamp resistance and the battery’s internal resistance, and which voltage do you use across the total resistance to find the actual current?

✅ Before You Answer

• Compute the lamp resistance using R = V² / P and double-check the units (ohms, watts, volts). • Make sure you add the internal resistance to the lamp resistance before calculating total current. • Use the correct formula I = V / R_total for the actual circuit and compare your numerical result to the answer choices.