Fuse continuity test: When checking a 2 A fuse with a multimeter set to measure resistance (Ohms), what reading indicates a good fuse element (i.e., intact conductor)?

Introduction / Context:Fuses protect circuits by opening under excessive current. A basic bench check for a fuse is a continuity or resistance test. Understanding the expected reading prevents unnecessary replacements and speeds diagnostics.

Given Data / Assumptions:

• The fuse is removed from the circuit and measured directly.
• The meter measures resistance between fuse end caps.
• We assume a standard intact fuse with a low-resistance metal element.

Concept / Approach:

A good fuse is simply a short piece of wire designed to melt at a specified current. Its resistance is extremely low. An ideal measurement trends to 0 ohms. Real meters may show a few tenths of an ohm due to lead resistance, but the conceptual target is 0 ohms to indicate continuity. High or infinite resistance indicates a blown fuse.

Step-by-Step Solution:

Verification / Alternative check:

Use the continuity mode: a steady tone confirms a low-resistance path. Visually inspecting the fuse element can corroborate the measurement but is less reliable for slow-blow types.

Why Other Options Are Wrong:

• 2.0 or 5.0 ohms: Too high for a healthy fuse, implying resistance where there should be near-zero.
• 0.2 ohm: Could reflect lead resistance, but the best conceptual answer is 0.0 among the given discrete choices.
• None of the above: Incorrect since 0.0 represents a good fuse.

Common Pitfalls:

Measuring in-circuit leading to misleading readings; not zeroing test leads; confusing continuity tone thresholds with actual resistance values.

Final Answer:

0.0