Which unit describes a small electrical current often used in esthetic devices?

Which unit describes a small electrical current often used in esthetic devices?

• A. Watt
• B. Milliampere
• C. Kilowatt
• D. Volt

Answer: (B)

The concept here is how current is measured in electrical devices. The basic unit for current is the ampere, but for the small currents commonly used in esthetic equipment, we describe them with milliampere (mA), where 1 mA is one-thousandth of an ampere. Using milliampere reflects that these devices operate with gentle, skin-safe currents. Watt and kilowatt measure power (how much energy is being used per second), not the amount of current flowing, and volt measures electrical potential difference, not current. So milliampere is the appropriate unit to describe the small currents found in esthetic devices.

The concept here is how current is measured in electrical devices. The basic unit for current is the ampere, but for the small currents commonly used in esthetic equipment, we describe them with milliampere (mA), where 1 mA is one-thousandth of an ampere. Using milliampere reflects that these devices operate with gentle, skin-safe currents. Watt and kilowatt measure power (how much energy is being used per second), not the amount of current flowing, and volt measures electrical potential difference, not current. So milliampere is the appropriate unit to describe the small currents found in esthetic devices.