In some texts, the interquartile range is defined differently. It is defined as the difference between the largest and smallest values in the middle 50% of a set of data. To compute an interquartile range using this definition, first remove observations from the lower quartile.
A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays. Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal.
Top 10 facts about the world. An electrical relay is a switch that is under the control of another circuit. A classic example is the system used to start a car â when someone turns an ignition key, the ignition does not interact directly with the car battery. Instead, it activates a relay, which passes the signal on so that the car can start.