Field testing a fuse with a multimeter On a 2 A circuit, what resistance reading (Ohms) indicates a good fuse when measured out of circuit?

Introduction / Context:
Technicians routinely check fuses during no-power or intermittent faults. A fuse is simply a low-resistance conductor that opens under overcurrent. Understanding expected resistance helps avoid unnecessary part swaps.

Given Data / Assumptions:

• The fuse is removed from the circuit to avoid parallel paths.
• Digital multimeter is functioning and zeroed (or using relative mode).
• Fuse rating is 2 A, but rating does not materially change its intact resistance being near zero.

Concept / Approach:

A good fuse presents very low resistance (ideally approaching 0 Ohms). In practice, contact resistance and meter lead resistance may show a small value, but conceptually a “good” reading is near zero. An open fuse will read infinite or very high resistance.

Step-by-Step Solution:

Verification / Alternative check:

Continuity beepers confirm a low resistance path; visual inspection sometimes shows a broken element, but measurement is more reliable.

Why Other Options Are Wrong:

0.2 Ohm may occur due to lead resistance, but the best textbook answer is 0.0 to represent a closed conductor. 5.0 and 2.0 Ohms are far too high for a fuse and indicate excessive drop or a measurement error.

Common Pitfalls:

Measuring in-circuit (parallel paths give false readings); not zeroing lead resistance; assuming a visually intact fuse is necessarily good.

Final Answer:

0.0.