What type of device would be connected to the dental unit via electric cord and is operated by foot?

The device that is connected to the dental unit via an electric cord and operated by foot is a rheostat, which serves as a foot control. This component allows dentists or dental assistants to regulate the power supplied to dental handpieces and other tools, providing precise control over their operation without the need for hands-on adjustment.

The foot control design facilitates multitasking during procedures, enabling the operator to keep their hands free to manage other instruments or patient care tasks. Because of its role in controlling the speed and performance of dental equipment, the rheostat is an essential tool in the dental practice, enhancing both efficiency and effectiveness during procedures.

In contrast, devices like the air syringe and suction device do not use foot operation; they are typically activated by hand or are built into the dental unit’s controls. A mobile cabinet is a storage solution and does not connect electrically to the dental unit. Therefore, the rheostat distinctly fits the description of being an electrically connected device that is operated by foot.