Which unit is used to measure electric strength?

The correct choice for measuring electric strength is the Volt. Electric strength refers to the ability of a material to withstand electric fields without breaking down, which is quantified by the voltage.

Voltage is the potential difference that drives electric current through a circuit, and it reflects the force that pushes electrons through a conductor. A higher voltage means a stronger electric field can be applied, indicating the material's ability to resist electrical breakdown.

Units like Amp, Ohm, and Watt relate to other electrical characteristics such as current, resistance, and power respectively and do not directly measure electric strength. Understanding these basic electrical principles is essential for anyone entering the field of esthetics, particularly in areas involving electrical equipment and treatments.