Which of the following is the switching device for a key-operated lock?

Which of the following is the switching device for a key-operated lock?

• A. Cylinder
• B. Key
• C. Bolt
• D. Combination

Answer: (B)

In a key-operated lock, the key is the switching device because it is the element that makes the internal mechanism change state. When the key is inserted and turned, its cuts align the pins or wafers inside the cylinder at the correct shear line, allowing the cylinder to rotate. That rotation enables the mechanism to retract or extend the bolt, which is what actually locks or unlocks the door. The cylinder is the housing that contains the movable pins and rotates under the key, while the bolt is the part that physically blocks or releases the door. A combination refers to locks that use digits rather than a key.

In a key-operated lock, the key is the switching device because it is the element that makes the internal mechanism change state. When the key is inserted and turned, its cuts align the pins or wafers inside the cylinder at the correct shear line, allowing the cylinder to rotate. That rotation enables the mechanism to retract or extend the bolt, which is what actually locks or unlocks the door. The cylinder is the housing that contains the movable pins and rotates under the key, while the bolt is the part that physically blocks or releases the door. A combination refers to locks that use digits rather than a key.