A 9.0 volt battery is connected to four resistors in a parallel circuit. The resistors have 7.0 Ω, 5.0 Ω, 4.0 Ω, and 2.0 Ω respectively. What is the total resistance in the circuit?
A .09 Ω
B 0.917 Ω
C 18 Ω
D 9.8 Ω
The total resistance is the reciprocal of (1/7+1/5+1/4+1/2) = 0.915 ohm. The battery voltage makes no difference. It would be 0.915 ohm even if the resistors were connected in parallel and just laying in the drawer.
