1. The problem statement, all variables and given/known data It says, The potantial difference between K-L = V , when the key is closed... And asks whats the potantial difference between K-L, when the key is open ? ----- You see 2 drawings, 1 above the question, 1 below the question, I have drawed these, these shows us the different waypaths, electric would follow as being related to the key. But i couldn't bring this question to the solution... Can you show me ? Exactly i dont know what i have to do too... I did, what i could do.