Final answer:
The grid ratio of a grid with lead strips that are 4.0 mm high and 0.25 mm apart is calculated by dividing the height by the distance between strips, resulting in a grid ratio of 16.
Step-by-step explanation:
The grid ratio is defined as the ratio of the height of the lead strips to the distance between them. In this case, the height of the lead strips is 4.0 mm and the distance between the strips is 0.25 mm. To find the grid ratio, you can use the following formula:
Grid Ratio = Height of the strips / Distance between the strips
Plugging in the given values:
Grid Ratio = 4.0 mm / 0.25 mm
Grid Ratio = 16
Therefore, the grid ratio for this particular grid is 16.