The sum of the currents flowing through each branch of a parallel circuit is equal to the total current flow in the circuit. Using Ohm's Law, the branch current for a three branch circuit equals the applied voltage divided by the resistance as shown in equations (2-6), (2-7), and (2-8).

Example 1: Two resistors, each drawing 3A, and a third resistor, drawing 2A, are connected

in parallel across a 115 volt source (Figure 23). What is total current?

Figure 23 Example 1 Parallel Circuit

Example 2: Two branches, R_l and R₂,are across a 120 V power source. The total current flow is 30 A (Figure 24). Branch R_l takes 22 amps. What is the current flow in Branch R₂?

Figure 24 Example 2 Parallel Circuit

Example 3: A parallel circuit consists of R₁ = 15, R₂ = 20 and R₃ = 10, with an applied voltage of 120 V (Figure 25). What current will flow through each branch?

Figure 25 Example 3 Parallel Circuit