The symbol for alternating current voltage is “~”. This symbol is used to indicate that the voltage is constantly changing direction and magnitude over time, in contrast to direct current voltage, which flows in only one direction and has a constant magnitude. The “~” symbol is placed after the voltage value to indicate that it is an AC voltage and not a DC voltage. For example, if a voltage is measured as “120V~”, it means that the voltage is 120 volts and is alternating current.