Question

Set up a parallel circuit with three resistors. Set up the battery to be 9 V, one resistor at 10 Ohms, the other at 21 Ohms, and the last at 13 Ohms. What is the equivalent resistance of this circuit? What is the average current of the circuit?

Answer 1

In a parallel circuit, the equivalent resistance is the reciprocal of (the sum of the individual reciprocals).

1/R = 1/10 + 1/21 + 1/13

1/R = 0.225 mhos

R = 4.45 ohms

I = V / R

The total current out of the battery is

I = (9v)/(4.45ohms)

I = 2.02 Amperes

As the total current leaves the battery, it splits into 3 paths, and each resistor gets part of it. The 10ohm resistor gets the most current; the 21ohm resistor gets the least current. After flowing through the resistors, the 3 currents join and add up to 2.02 Amperes again, and the same current returns to the battery.

Each resistor has the same 9v of EMF across it.