1. The problem statement, all variables and given/known data If the diameter of a wire (conductor) is dimidiated , then its resistance: A Remains unchangable B is diminiated C Becomes two times greater D Becomes 4 times greater 2. Relevant equations R=constant*length/Surface 3. The attempt at a solution Cross sectional area=pi r^2=pi (D/2)^2=piD^2/4 Then the resistance becomes 4 times greater. But in my book the answer is C.