Draw the steady-state, direct- and quadrature-axis phasor diagram for a salient-pole synchronous motor with reactances Xd and Xq and armature resistance Ra. From this phasor diagram, show that the torque angle δ between the generated voltage Eaf (which lies along the quadrature axis) and the terminal voltage Vt is given by Here Ф is the phase angle of the armature current Ia a and Vt, considered to be negative when Ia lags Vt.