🔍 Key Concepts

• Use Ohm's Law (V = I × R) to relate voltage, current, and resistance • Identify whether the resistors are in series or parallel, since that affects how voltage divides • Understand voltage division in series circuits: total source voltage is shared among series resistors in proportion to their resistances

💭 Think About

• First, determine the total resistance and current in the circuit (if possible from the figure). How would you find current from the source voltage and total resistance? • Once you know the current, how can you use the resistance of R1 to find the voltage drop across it? • If R1 is in series with other resistors, how is the total source voltage split between them based on their resistance values?

✅ Before You Answer

• Verify the circuit configuration from Figure 3B2: is R1 in series, parallel, or part of a mixed network? • Confirm the source voltage and the resistance value of R1 from the figure before calculating • Double-check unit consistency: voltage in volts (V), resistance in ohms (Ω), current in amperes (A) when applying Ohm’s Law