223. In figure of «A» of the illustrated circuit, what is the voltage measured across R1 if the battery voltage is 24 volts, the resistance of R1 is 34 ohms, and the resistance of R2 is 126 ohms when the switch is closed

The voltage across R1 is 5.1 volts. In a series circuit, the total resistance is the sum of individual resistances. Using Ohm's Law (V=IR), the current through the circuit is calculated as 0.15 amps. Applying Ohm's Law to R1, the voltage drop is 0.15 amps * 34 ohms = 5.1 volts.