What is the voltage across 'R1' of figure "B" of the illustrated circuit with the switch closed if the applied voltage is 24 volts and resistance of R1 is 3 ohms, R2 is 4 ohms, and R3 is 5 ohms, respectively? Illustration EL-0020

Correct Answer: Option B — 6 volts

Applying the voltage divider rule in a series circuit with resistors of 3, 4, and 5 ohms (total 12 ohms) connected to a 24-volt source, the voltage across the 3-ohm resistor R1 is calculated as $24 \times (3/12)$, equaling 6 volts.