If a DVOM is set to the 200 milliamp scale and the current increases to 2.5 amps, what is the meter likely to do?

• A. Continue to measure normally
• B. A negative reading
• C. Read 2.5 A
• D. Blow a fuse

Answer: (D)

When measuring current, the DVOM uses a low-value shunt and a protective fuse in the input path. The 200 mA scale is the maximum current that path is designed to handle. Pushing 2.5 A through that same path is far beyond its rating, which causes the protective fuse to open to prevent damage. So the meter is likely to blow its fuse, interrupting the circuit and leaving a zero or “OL” reading until the fuse is replaced. It won’t continue to measure normally, won’t show a valid 2.5 A, and a negative reading isn’t expected from this overload. If you need to measure higher current, you’d switch to the appropriate high-current range or use a different method (like a clamp meter).