Instrument placement — to measure a branch current, an ammeter is placed in series with that branch; to measure the total current drawn from the supply in a parallel circuit, the ammeter is placed in series with the source lead.

Introduction / Context:
Ammeter insertion must not change the circuit’s node-to-node voltages significantly. Ideal ammeters have very low resistance and are inserted in the path of the current being measured.

Given Data / Assumptions:

• Ideal ammeter (negligible internal resistance).
• Parallel circuit with multiple branches.
• Need to measure branch and total currents.

Concept / Approach:
Current is the same at every point in a series path; hence an ammeter must be placed in series with the intended path. For total current, insert the ammeter in series with one supply lead so all branch currents pass through it.

Step-by-Step Solution:

Verification / Alternative check:
KCL confirms the source current equals the sum of branch currents; the series supply ammeter thus reads the total.

Why Other Options Are Wrong:

Common Pitfalls:
Placing ammeters across a source (short circuit risk); confusing series vs parallel measurement rules.

Final Answer:
Series, series