Which term, literally, is a hole used to delay VSI pressure changes?

• A. Calibrated orifice
• B. Calibrated airspeed
• C. Cage
• D. Cabin altitude

Answer: (A)

The key idea is that the VSI uses a calibrated orifice—the tiny hole that vents air at a precise rate. This restricts how quickly the pressure inside the instrument can change as the aircraft moves through the air. Since the VSI indicates vertical speed by the rate of change of the static-pressure signal (a diaphragm responds to pressure differences), the restricted flow via the calibrated orifice creates a controlled lag. This lag smooths out brief fluctuations and makes the needle reflect how fast you’re climbing or descending, rather than your instantaneous altitude. The hole is literal and its restricted size is what delays the pressure changes the VSI relies on.

Calibrated airspeed relates to a velocity indication from the pitot-static system, not a delaying hole. A cage and cabin altitude are unrelated to this delay mechanism.