where the factor Lr/Lm allows us to include both the magnetizing and
the leakage flux produced by irq. Using the torque expression in chapter
10 of Reference [1] used in the previous course, and noting that the
current ird in the rotor d-axis winding flows through 3 / 2Ns turns, the
instantaneous torque on the d-axis rotor winding is (see problem 10-1
in chapter 10 of Reference [1])