In a N-stage sequence controller, each secondary is rated for Vs/n.

Explanation:
A sequence controller is a device used in power systems to control the sequential operation of various electrical equipment. It ensures that the equipment starts and stops in a specific order to prevent overloading or damage.

In a N-stage sequence controller, there are N secondary windings, each connected to a separate electrical load. The primary winding is connected to the power supply. The secondary windings are designed to have a specific voltage rating, Vs.

The voltage rating of each secondary winding in a N-stage sequence controller is given by Vs/n, where n represents the number of stages or secondary windings.

The reason for this is that the voltage across each secondary winding should be reduced to ensure proper operation of the connected electrical load. When multiple secondary windings are connected in a sequence controller, the total voltage is divided equally among them.

To achieve this division of voltage, the voltage rating of each secondary winding is set to Vs/n. This ensures that the voltage across each secondary winding is Vs/n, and the total voltage across all the secondary windings is Vs.

By providing the secondary windings with a voltage rating of Vs/n, the sequence controller ensures that each connected load receives the appropriate voltage level for its operation. This prevents overloading or damage to the electrical equipment.

Therefore, the correct answer is option c) Vs/n, where each secondary winding in a N-stage sequence controller is rated for Vs/n.