Which of the following traction systems uses 1 phase AC distribution network for minimum cost and high transmission efficiency with DC series motor?

The correct answer is 1) Composite system.

A composite system is a traction system that uses a combination of AC and DC power. In a composite system, the single-phase AC distribution network is used to transmit power to the locomotive. The locomotive then has a rectifier that converts the AC power to DC power. The DC power is then fed to the DC series motor.

Composite systems offer a number of advantages, including:

• Low cost: Composite systems are less expensive to build and operate than other traction systems, such as three-phase AC systems.
• High transmission efficiency: Single-phase AC power can be transmitted over long distances with high efficiency.
• Good performance: DC series motors offer excellent performance, with high torque at low speeds and high speed capability.

Composite systems are widely used in electric railways around the world. They are particularly popular in countries with developing economies, where the low cost and high efficiency of composite systems are important advantages.