A 220 V, 1200 rpm, 15 A separately excited motor has armature resistance and inductance of 1.8 Ω and 32 mH respectively. This motor is controlled by a single-phase fully-controlled rectifier with an ac source voltage of 230 V, 50 Hz. Identify the modes and calculate developed torques for:
I. 𝛼=60° and speed = 450 rpm
II. 𝛼=60° and speed 1500 rpm