The figure shows a circuit containing two batteries and thre

The figure shows a circuit containing two batteries and three resistors. The batteries provide Vemf,1 = 12.0 V and Vemf,2 = 16.0 V and have no internal resistance. The resistors have resistances of R1 = 29.5 Ohm, R2 = 41.5 Ohm, and R3 = 18.0 Ohm. Find the magnitude of the potential drop across R2- Additional Materials

Solution

Use superposition principle to find the voltage:

Vr2 = voltage across R2 due to V1 + voltage across R2 due to V2

= 12 * (41.5||18)/(29.5 + 41.5||18) - 16 *(41.5||29.5)/(18 + 41.5||29.5)

= 3.582 - 7.828

= --4.246

= 4.246 V