What is the definition of 'dynamic braking'?

Answer: B — technique for slowing down using traction motors

The definition of 'dynamic braking' refers to a technique for slowing down a train by using the traction motors. In this system, the traction motors, when operated in reverse, create a drag force that helps to reduce the speed of the train. This is accomplished by converting the kinetic energy of the moving train into electrical energy, which is then dissipated as heat in the resistors. Dynamic braking is beneficial because it allows for smoother deceleration and reduces wear on the mechanical braking components, as it relies on the train's existing propulsion system instead of mechanical friction. This technique enhances the overall efficiency and effectiveness of the braking system, particularly in longer trains that require gradual deceleration over extended distances. In contrast, options discussing brake pads or automatic brake force adjustments do not accurately define dynamic braking, as they focus on different braking methods or systems.