An MRI (or magnetic resonance imaging) scan is a radiology technique that uses magnetism, radio waves, and a computer to produce images of body structures. The MRI scanner is a tube surrounded by a giant circular magnet. The patient is placed on a moveable bed that is inserted into the magnet.
electrical switch. Thesaurus. Definitions of electrical switch. 1. n control consisting of a mechanical or electrical or electronic device for making or breaking or changing the connections in a circuit. switch for reversing the direction of an electric current. a switch that interrupts an electric circuit in the event of an overload.
tamper switch. 1  A switch that is activated when something is interfered with in a harmful or unauthorized manner. 2  Such a switch, for instance, may activate an alarm to indicate that a security mechanism is being meddled with.