Refer to the diagram on “Speed Controlof a Shunt Wound DC Motor, foundin the video on "Shunt, Series, andCompound wound motors". Supposethe no load voltage V = 90V, Ra + R1 =4 ohms, Rsh + RF = 150 ohms, and themotor runs at a rated speed of 1000RPM when IL = 4 amps. What is thearmature current IA in amps at therated speed?