220
In the U.S. and Canada: 120 V. In U.K. and Europe: 220 V. Elsewhere it will typically be either 120 V or 220 V, but other voltages are sometimes used.
110-120 Volts BUT IN SOME AREAS 220.
Mexico has 110 to 120 volts. SOME AREAS 220.
In the USA it is usually 120/208 or 120/240 volts In Europe I think it's 220 volts
The voltage cannot just be increased in a circuit because there is a risk of damage, blown circuit breakers and/or fire. However an appliance desgined to run on 220 v will use 6/11ths of the current used by an identical appliance designed for 120 v.
If the supply voltage is Vs and the equipment voltage is Va, then the equipment will work if Va = Vs (equation). But if Vs / Va = 220 / 120 (equation) the equipment will fail.
No, the source voltage can not change to a lower voltage without using equipment to do so.
No, a 120-volt LED lamp should not be used in a 220-volt socket, as it can cause the lamp to fail or even pose a fire hazard. The voltage difference can damage the lamp's internal components. If you need to use a 120-volt lamp in a 220-volt environment, consider using a step-down transformer or a voltage converter designed for this purpose. Always ensure compatibility to avoid safety risks.
read the label on your charger if it says 90v to 250V it will be ok it it says 120V it will not be ok
A 220 volt line may put out 250 volts because this specification features voltage that varies between 220 and 250 volts. In other countries, the electricity varies in voltage between 110-120 volts.
The U.S. chose 110-120 volts because it is safer than 220-240 volts. Far less chance of getting electrocuted on the lower voltage.