The device that allows an object to remain upright when the base tilts is called a?

• A. Ball bearing
• B. Universal joint
• C. Rigid linkage
• D. Gimbal ring

Answer: (C)

To keep something upright as the base tilts, you use a gimbal system. A gimbal consists of rings connected by pivots that let the mounted object rotate freely about two perpendicular axes. This setup decouples the object's orientation from the base’s tilt, so the object remains level with gravity even when the support tilts. In aviation instruments, this is why gyros and displays use gimbals—the inner frame can stay oriented while the outer structure tilts.

A ball bearing mainly reduces friction and doesn’t control orientation. A universal joint transfers angular motion but doesn’t inherently keep the output upright when the input tilts. A rigid linkage would move with the base, causing the object to tilt along with it. Hence, the device that preserves upright orientation despite base tilt is the gimbal ring.