PHYSICS · Subjective · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits
Problem
In the two-loop circuit described below, only the 8.0 Ω resistor has a tolerance of ±0.2 Ω; all other quantities are exact.
• Left loop: a 20.0 V battery, a 4.0 Ω resistor, and the shared 8.0 Ω resistor.
• Right loop: a 10.0 V battery with the same clockwise orientation, a 6.0 Ω resistor, and the same shared 8.0 Ω resistor.
Clockwise loop currents I_L (left) and I_R (right) are defined, so that the current through the shared resistor equals I_L − I_R from left to right.
Calculate the current through the shared resistor using the nominal 8.0 Ω value, and state the percentage uncertainty in that current that arises solely from the ±0.2 Ω tolerance of the shared resistor.