Question

7. You are pinned down in combat with no working radio, however, you know that you could call in
reinforcements if you found a way to MacGyver a replacement coil for your radio and connect it to
your portable power source with a voltage of V = 20V . You do have enough copper wire (?Cu =
1.68 · 10?8?m) with a diameter of d = 0.3mm to build an l = 15cm long coil that has N = 850 loops.
Each loop requires roughly 6cm wiring. a) Calculate the DC-resistance that your coil would have. b)
Given your power supply and the DC-resistance, calculate the current that flows through the coil when
it is connected to the power source. c) When a current flows through the coil, a magnetic field is
created. What is the magnetic flux density of your coil during operation?

Answer 1