Three resistors (15, 20, 25 ohms in this order) are connected to a 13-V battery . The internal resistance of the battery is negligible. What is the voltage difference across the 20-Ω resistance?

Answer 1

I=E/(R1+R2+R3)=13/(15+20+25)=0,217 Amps.

V = I*R2 = 0.217 * 20 = 4.33 Volts.