Based on the answers provided, here are the corrections needed for the 3D object:

1. The rectangle on the top surface of the cylinder needs to be repositioned so that it is centered on the cylinder. This means it should align with the central axis of the cylinder.

2. The dimensions of the rectangle need to be adjusted. Its width should be about 4/5th the diameter of the cylinder. 

3. The height of the rectangle should also be adjusted to be about 1/10th the width of the rectangle. 

Please make these changes to ensure the 3D object meets all the required specifications.