____ robots pick up an object, rotate, and then places the object.

• A. articulated
• B. cartesian
• C. cylindrical
• D. polar

Answer: (C)

Rotating the object while it’s held is most naturally done by a robot that includes a base rotation around a vertical axis along with vertical and radial motion. A cylindrical robot has exactly that: a rotating base (theta) plus a vertical (z) and radial (r) movement. This lets the end effector grab the object, rotate it by turning the base, and then lift or extend to place it at the destination. Because the rotation is built into the cylindrical form, the sequence of pick → rotate → place can be accomplished smoothly using the same arm. In contrast, Cartesian robots move in straight lines along X, Y, and Z without an inherent rotation of the end effector; articulated arms are very flexible but are a general family not defined by this single-axis rotation mechanism; polar configurations can also provide rotation but are less commonly used for this straightforward pick-and-place task.