Safety and work practicesQuestion 310 of 1506

Why should you check a locked-out circuit for both AC and DC voltage?

The AC mode is less accurate than the DC mode
DC checks protect the meter fuse from damage
The Start button test requires both modes
AC mode misses DC, and both can be deadly

Show answer

Correct answer: AC mode misses DC, and both can be deadly

A meter set to AC does not register DC and the other way around, so one mode can miss a hazard.

Source: Troubleshooting Motors and Controls (Dickson-Self), 1.3: Meter Usage

Questions last reviewed: 18 October 2026

Red Seal Electrician Practice needs JavaScript to run. Use its questions for practice. The real pass mark is usually 70%. Check it with your province or territory's apprenticeship office.