Introduction:
When selecting an electric motor for a flour mill, various electrical characteristics need to be considered. These characteristics determine the motor's performance, efficiency, and suitability for the specific application. Among these characteristics, the least significant one is the braking capability of the motor.

Explanation:

1. Starting characteristics:
Starting characteristics refer to the motor's ability to start the load attached to it. It includes parameters such as starting torque, starting current, and starting time. These characteristics are crucial in ensuring that the motor can start the flour mill efficiently and reliably. If the motor lacks sufficient starting torque or takes too long to start, it may result in operational issues and delays in the flour mill's production.

2. Running characteristics:
Running characteristics encompass the motor's performance during normal operation. These include parameters such as rated power, speed, efficiency, and load-carrying capacity. The motor should be capable of delivering the required power and maintaining the desired speed under normal operating conditions. The efficiency of the motor is also important as it affects energy consumption and operational costs.

3. Efficiency:
Efficiency is a critical factor in motor selection as it directly affects the operating costs of the flour mill. A more efficient motor utilizes electrical energy more effectively, resulting in lower energy consumption and reduced electricity bills. High-efficiency motors also produce less heat, which contributes to improved reliability and longevity.

4. Braking:
Braking capability refers to the motor's ability to decelerate or stop the load when necessary. In the context of a flour mill, braking may be required to halt the mill's operation quickly or to prevent the mill from running out of control. However, the braking characteristic is the least significant in motor selection for a flour mill because:

- Flour mills typically have external braking systems specifically designed for controlling the mill's rotation and stopping it efficiently. These systems are separate from the motor and are responsible for providing the necessary braking force.
- Electric motors used in flour mills are generally not designed to provide significant braking torque. Their primary function is to provide rotational motion to the mill, and braking is secondary.
- If the motor lacks adequate braking capability, it can be compensated by using an appropriate external braking system without compromising the motor's overall performance and suitability for the flour mill application.

Conclusion:
Among the various electrical characteristics considered when selecting an electric motor for a flour mill, the least significant one is the braking capability. Starting characteristics, running characteristics, and efficiency play more crucial roles in ensuring the motor's performance, reliability, and cost-effectiveness. Although braking capability is necessary, it can be achieved through separate external braking systems specifically designed for controlling the flour mill's operation.