12 Volts DC
No, auto batteries are DC not AC.
115 Volt and a 110 Volt can be treated as the same thing. The electrical voltage supplied from your electric company is not exact and can be 120 Volt + or - 10%.
put double power batteries in
If your electrical service is only 120 volts you have a problem. There is no way that you can connect a 240 volt cook top to that service. You have two options, one is to upgrade to a new 120/240 volt electrical service. Your other option is to find a 120 volt electrical cook top.
Yes, the rating on the receptacle is the maximum amount of voltage that is legally allowed to be applied to the device.
There are no three phase 120 volt systems.
Yes, the heater is a 240/120 heater, but I want to operate as 120 volt
Can you use a 120 volt bulb in a 130 volt socket?
You tell yourself the 125 volt receptacle is a 120 volt receptacle. They're the same thing.
If you want your bulbs to last longer then use 130 volt bulb on a 120 volt system. The light emitted by a 130 volt bulb, when comparing it to a 120 volt bulb, will be a bit dimmer.
Use a volt meter Plug a 120 volt accessory into it
Generally, yes. Most US home services are 220 volt (240, 220 are `nominal' names) which are split into two 120 volt legs. You can find wiring information ont he internet, but generally, the 220 volt systems have a 120 volt leg, a common ground and then another 120 volt leg. Added together, they're 220 volt but by splitting them, you'll end up with two 120 volt legs. If you're not sure about how to wire them up, contact a qualified electrician to help you. House wiring can be very dangerous if you don't know what you're doing as well as lethal. When in doubt, don't.