During dynamic braking, the motor operates as which device after the main power is removed?

• A. DC generator
• B. DC motor
• C. AC generator
• D. AC motor

Answer: (A)

Dynamic braking uses the inertia of the spinning motor to generate electricity instead of consuming it. When the main power is removed, the rotor keeps turning and induces a voltage in the windings. This generated current flows through a braking circuit (usually a resistor), and the electrical energy is dissipated as heat. The act of generating current creates a braking torque that opposes the motor’s rotation, slowing it down. Since a DC motor becomes a generator when it’s turning without supply, this braking method relies on the motor operating as a DC generator to convert kinetic energy into electrical energy for dissipation. The other options describe devices that would require active power input or refer to AC machines, which isn’t how dynamic braking operates.