If the label has indicated that the input voltage is 50-60Hz, such as a mobile phone charger, there is no problem.
A physical quantity that measures the energy difference of unit charge in electrostatic field due to different potentials. Its magnitude is equal to the work done by the unit positive charge moving from point A to point B under the action of electric field force, and the direction of voltage is defined as the direction from high potential to low potential.
Extended data:
For circuit analysis, one of the most important variable voltages is sinusoidal AC voltage, whose magnitude and direction change periodically according to sinusoidal law with time.
Based on the voltage value of electrical equipment to ground. The voltage to ground is higher than or equal to 1000 volts. The voltage to ground is lower than 1000 volts.
Potentiometer is a precise instrument for accurately measuring electromotive force or potential difference by using compensation principle. This compensation method has high measurement accuracy.
Baidu encyclopedia-voltage