In one kind of computer keyboard, each key is mounted on one end of a plunger. The other end of the plunger is attached to a movable metal plate. Refer to the figure given.
The dielectric material between the two plates is made of a soft material and is compressible. The combination of the two plates and the dielectric between them constitutes a capacitor.
Each key on the keyboard when pressed is recognized due to which one of the following factors?
A. The pressing of the key increases the capacitance of the capacitor below the key due to a decrease in separation between the plates.
B. The decrease in the thickness of the soft dielectric layer decreases the capacitance of the capacitor below the key.
C. The momentary decrease in the space between the plates of the capacitor is detected as a mechanical sound signal of a specific frequency.
D. all of the above
