Instrumentation – Electric current is measured by which instrument?

Introduction / Context:
Electrical measurements rely on standard instruments, and knowing which device measures which quantity is foundational for physics, electronics, and engineering labs. This item asks specifically about measuring electric current.

Given Data / Assumptions:

• Sought quantity: electric current (symbol I), typically in amperes (A).
• We must match it with the correct measuring instrument.
• Options include both electrical and non-electrical instruments/parts.

Concept / Approach:
An ammeter is designed to measure current in amperes. In circuits, ammeters are connected in series so that the entire current flows through the meter. Voltmeters, by contrast, measure potential difference and are connected in parallel. Familiarity with these roles prevents wiring errors and instrument damage.

Step-by-Step Solution:
Identify required measurement: current (A).Recall instrument mapping: current → ammeter; voltage → voltmeter; wind speed → anemometer.Confirm that a commutator is a machine component, not a meter.Select “ammeter”.

Verification / Alternative check:
Memory aid: names often cue the quantity—“ammeter” (ampere), “voltmeter” (volt), “ohmmeter” (ohm). A multimeter can measure several, but here the single-purpose device is requested.

Why Other Options Are Wrong:

• commutator: part of a DC machine; it reverses current direction, does not measure.
• anemometer: measures wind speed, not electric current.
• voltmeter: measures voltage, not current.

Common Pitfalls:
Confusing ammeter and voltmeter connections (series vs parallel) or assuming any meter can measure all quantities.

Final Answer:
ammeter