Is Kirchoff 's Voltage Law valid for a circuit with a component with infinite resistance -LRB- an `` open '' circuit -RRB- ?
How can one show that the magnetic field due to an infinitely long current carrying conductor at a point near its end is given by B = -LRB- μ0 -RRB- I / -LRB- 4πa -RRB- using Ampere 's Circuital Law -LRB- preferably -RRB- or Biot Savart 's Law ?