Q7. a) D.C. motors are used where very high torque and/or precise speed control is required. How does the control of magnetic field flux and armature current relate to the starting characteristics of a D.C. motor in such applications? (6)
b) A 220 V, D.C. shunt motor has an armature resistance of 0.5 ohm and an armature current of 40 A on full load. Determine the reduction in flux necessary for a 50 per cent reduction in speed. The torque for both conditions can be assumed to remain constant. (10)
Username or email address *Required
Password *Required
Note: Entering wrong username in the login form will ban your IP address immediately. Entering wrong password multiple times will also ban your IP address temporarily.
Log in
Lost your password? Remember me
No account yet?