iam in total confusion how to calculate volatege and current i knw forumula v=ir i need is there any easy methode to calculate rating on an breaker

 

Is that a circuit breaker? If so, it will be spec'ed as to voltage. Perhaps you can give us some more information about the circuit you wish to protect?

 

Hello,

If it is about a circuit breaker (wich is a safety device) tahe a look at the links of this page:
http://www.educypedia.be/electronics/safety.htm

(the used language is behind the link in red).

Bertus