What would be the voltage drop across the series string of the circuit shown in figure "A" of the illustration if the source voltage is 30 volts, the resistance for R1 is 10 ohms, the resistance for R2 is 10 ohms and the resistance for R3 is 10 ohms? Illustration EL-0032

Correct Answer: Option D — 30 volts

Kirchhoff's Voltage Law dictates that the sum of voltage drops around any closed loop must equal the applied source voltage. For three identical 10-ohm resistors in a purely series string connected to a 30-volt source, the entire 30 volts drops across the string.