The parameters for a DC Motor used in an electric vehicle are Rated Armature Voltage Va,rated = 72V, Rated Armature Current Ia,rated = 400A, Ra = 0.5Ω, La = 8mH, kΦ = 0.7 V-sec. Derive the torque-speed characteristics for the DC motor. Find the steady state operating point if the vehicle T-Ω characteristics on a grade of -5.24?