For a perfectly rigid body, the elasticity is:
| 1. | unity | 2. | zero | 
| 3. | infinite | 4. | indeterminate | 
Select the incorrect definition:
| 1. | Deforming Force: A force that changes the configuration of a body. | 
| 2. | Elasticity: The property of regaining the original configuration. | 
| 3. | Plastic body: A body that can be easily melted. | 
| 4. | Elastic limit: The point beyond which a material begins to flow. |