Define DC traction and provide an example.

Define DC traction and provide an example.

• A. A traction system powered by direct current, such as 750V DC for metro systems.
• B. A traction system powered by alternating current.
• C. A system that converts DC to AC for traction.
• D. A traction system using only alternating current.

Answer: (A)

DC traction means a railway propulsion system that is powered by direct current fed to the traction motors, typically available through overhead lines or a third rail. This setup is common in urban rail because DC motors provide strong starting torque and straightforward control for frequent stop-and-go service. An example is 750 V DC used in many metro networks. Other options describe different systems: alternating current traction uses AC supply, while converting DC to AC is just a conversion step and not the traction type itself. A system that uses only alternating current would be AC traction, not DC traction.

DC traction means a railway propulsion system that is powered by direct current fed to the traction motors, typically available through overhead lines or a third rail. This setup is common in urban rail because DC motors provide strong starting torque and straightforward control for frequent stop-and-go service. An example is 750 V DC used in many metro networks.

Other options describe different systems: alternating current traction uses AC supply, while converting DC to AC is just a conversion step and not the traction type itself. A system that uses only alternating current would be AC traction, not DC traction.