Reversing the direction of rotation in a DC shunt motor is achieved by changing the polarity of either the field winding or the armature winding, but not both. Reversing the polarity of one winding flips the direction of its magnetic field, which interacts with the current in the other winding, resulting in a change of torque and direction of rotation.
The back EMF in a DC motor opposes the supply voltage. This is explained by _____________.
Which of the following statements related to the speed control of DC shunt and series motors is correct?
In a brake test, the DC motor took 20 A from a 200 V supply mains. The brake pulley of radius 10 cm had an effective load of 20 kg and the speed was 10 rps. The value of BHP (in metric) is _________.
