With reference to the term mechanical advantage, velocity ratio and efficiency of a machine, name and define the term that will not change for a machine of a given design.

Explanation

To answer the question regarding which term does not change for a machine of a given design, we will analyze the concepts of mechanical advantage, velocity ratio, and efficiency.

### Step-by-Step Solution:

1. **Understanding the Terms**:
- **Mechanical Advantage (MA)**: This is the ratio of the load force (output force) to the effort force (input force) applied to the machine. It indicates how much the machine amplifies the input force.
- **Velocity Ratio (VR)**: This is the ratio of the distance moved by the effort to the distance moved by the load. It represents how much the machine changes the speed of the input force compared to the output force.
- **Efficiency (η)**: This is the ratio of the mechanical advantage to the velocity ratio, expressed as a percentage. It indicates how effectively the machine converts input work into output work.
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