so i found the torque for 300v and did the following:You know both the torques (at 300V, 30A and at 260V, 30A).
Hint: As I said earlier, torque is proportional to the product of field current and armature current.
T(300) / T(260) = I(f)1 / I(f)2 (as Ia cancel out because they are the same)
and then I(f) = Vdc / Rf + Radj
but i end up getting 20 ohms for my answer which was the same as the original?
What am i doing wrong here?