What is the formula for finding total current in a parallel circuit when component currents are known?

What is the formula for finding total current in a parallel circuit when component currents are known?

• A. IT = I1 + I2 + I3 + ⋯ IN
• B. IT = I1 = I2 = I3 = ⋯ IN
• C. IT = I1 − I2 − I3 − ... IN
• D. IT = I1 × I2 × I3 × ...IN

Answer: (A)

In a parallel circuit, the total current is the sum of the currents in each branch because current splits among the parallel paths and then recombines back at the junction. The source has to provide all the branch currents combined, so the total current is IT = I1 + I2 + I3 + ... + IN. Other forms don’t fit this situation: it isn’t simply equal to one branch current, it isn’t subtracted, and it isn’t multiplied, since currents in parallel add up rather than multiply or cancel.

In a parallel circuit, the total current is the sum of the currents in each branch because current splits among the parallel paths and then recombines back at the junction. The source has to provide all the branch currents combined, so the total current is IT = I1 + I2 + I3 + ... + IN.

Other forms don’t fit this situation: it isn’t simply equal to one branch current, it isn’t subtracted, and it isn’t multiplied, since currents in parallel add up rather than multiply or cancel.