How can you quickly verify if a line has continuity?

• A. Visual inspection alone.
• B. Testing with a signal generator to hear a tone.
• C. Using a continuity tester or a multimeter to check that resistance is low between conductors.
• D. Substituting components until it works.

Answer: (C)

Continuity means there is a complete electrical path between two points. The quickest way to verify that is to measure the resistance between the conductors with a continuity tester or a multimeter on its ohms range. If the line is intact, the reading is a very low resistance (often nearly zero) and many testers will beep to signal a closed circuit. If the path is broken, the resistance will be very high or infinite, indicating an open line.

In practice, you should power down and disconnect the line from other circuits before testing, and test between the corresponding conductors to confirm a proper path along the line itself. Visual inspection can miss internal breaks, corrosion, or damaged insulation, so a resistance check gives a far more reliable read on continuity. Using a signal generator to hear a tone might show there’s some path, but it doesn’t quantify how solid the connection is, and substituting components blindly can hide or create issues.