Hi. the equation R=resistivity * (L/A) does make the resistance directly proportional to the length. It also make it inversely proportional to the cross sectional area. this does not make sense to me. Given the same wire and length, the bigger (cross sectional area) wire should have a larger resistance. But according to the equation, this works in reverse. Common sense doesn't "make" sense. I am a little confuse. please clarify. Thanks.