Technician A says that a solenoid can be tested by inspecting mechanical movement. Technician B says that a solenoid can be tested electrically. Who is right?

• A. A only
• B. B only
• C. Both A and B
• D. Neither A nor B

Answer: (C)

A solenoid is an electromechanical device, so to verify it works you should check both how it behaves electrically and how the plunger moves mechanically. Electrically, you test the coil by measuring its resistance and, if possible, the current draw at the rated voltage to confirm the coil isn’t open or shorted and that it draws the expected current. Mechanically, you energize the solenoid and observe the plunger for full, smooth movement and reliable return when power is removed, ensuring there’s no sticking or binding. If the coil shows proper electrical characteristics and the plunger moves correctly, the solenoid is functioning well. If either test fails, it points to a fault in either the electrical path or the mechanical action. Since both approaches are valid and complementary, both statements are correct.