A physical quantity sensor includes a sensor portion, a casing, and a vibration isolator. A foldable roof preferably includes a rear window disposed within a rear roof portion and the foldable roof can be stored substantially completely within the vehicle body and below the window shoulder line. An air gap defined between the outer yoke and the inner yoke. The power control may be used for rip sawing or miter cutting on a table saw, on a hand-held router or a router table, on a jointer, a band saw, a disk sander, a drill press, or on other conventional power tools having a working head for cutting or shaping a workpiece.