There are no volts in a light. A light consumes power.
As many as you want. But where do you find 640 volts RMS?
6 volts
Onions don't have volts.
it varys from light bulb to light bulb.
15.
6
The correct voltage should be printed on the light bulb.
amps equals watts divided by volts.
For lighting up a city you need 120 volts in the USA and 230 volts in Europe. It's just the usual voltage the light bulbs are needing.
It honestly depends on the type of flash light.
.63 ampere draw @ 7 volts
You generally need the same number of volts for a given amount of light (lumens), regardless of how many hours you use it. They typically measure the amount of energy used by a bulb in "watts", not volts, and you can find a wide range of wattage ratings from milliwatt LEDs to 1000-watt floodlights and on up.