What happens to film density when you increase exposure time while keeping other factors constant?

When exposure time is increased while keeping all other factors constant, the film density increases. This increase in density occurs because greater exposure time allows more radiation to interact with the film emulsion, leading to a higher accumulation of latent image density. The film responds to the increased amount of radiation by darkening more, resulting in higher density in the developed radiograph.

In radiographic testing, it is essential to control exposure parameters effectively; thus, understanding the relationship between exposure time and film density is critical for achieving the desired imaging results. The other potential outcomes, such as remaining constant or decreasing, would not occur under the conditions specified, where other factors remain unchanged.