Back-siphonage is caused by which condition in the water supply system?

Back-siphonage is caused by which condition

Multiple choice — select the best answer

APressure downstream exceeding supply pressure
BA faulty check valve failing to close
CThermal expansion in a closed system
DNegative pressure (vacuum) in the supply line

✓ Correct answer: D. Negative pressure (vacuum) in the supply line Back-siphonage is the backflow of potentially contaminated water caused by a negative pressure (partial vacuum) in the supply piping, similar to the siphon effect. It can occur during water main breaks or high-demand events.

.q-expl{display:block!important}.q-opt[data-idx="3"]{border-color:#16a34a;background:#f0fdf4}.q-opt[data-idx="3"] .oltr{background:#16a34a;color:#fff}.q-opt{cursor:default!important;pointer-events:none}

Keep practising. Use the free Journeyman Plumber 2 PDF, watch the YouTube walkthrough, or unlock all 10 web questions with timed mock exams.

Free PDF Video walkthrough

Topic: Backflow & Cross-Connection

← Previous Next → 🎲 Random question ↩ Back to all questions

Keep practising

Back-siphonage is caused by which condition in the water supply system?

Related questions — Backflow & Cross-Connection

Free practice here. Timed mocks when you are ready.