Final answer:
When power steering fails, the steering wheel locks and it becomes hard to steer the vehicle.
Step-by-step explanation:
If power steering fails, the steering wheel locks and it becomes impossible to steer the vehicle.
In a vehicle with power steering, a hydraulic system helps the driver steer the vehicle more easily. When the power steering fails, the hydraulic assistance stops, making it difficult to turn the steering wheel.
For example, if the power steering belt breaks or the hydraulic fluid leaks, the power steering system may fail and the steering wheel can become hard to turn.