In a parallel circuit, if one branch opens, what happens to the total current from the source?

• A. Total current decreases because one branch is removed.
• B. Total current stays the same.
• C. Total current increases because the remaining branches draw more.
• D. Total current becomes zero.

Answer: (D)

In a parallel circuit, the total current from the source is the sum of the currents in all the branches. If one branch opens, that branch draws no current, so the total current loses that branch’s contribution. The remaining branches still have the same voltage across them (assuming an ideal source), so their currents don’t suddenly increase; they stay the same as before. Therefore, the total current from the source decreases, not zero, unless every branch is open. For example, with three parallel branches each carrying I, the total is 3I. If one opens, the total becomes 2I.