A firm faces diminishing returns when its?

A firm faces diminishing returns when its marginal output diminishes. Diminishing returns occur when the addition of one more unit of an input, such as labor or capital, to the production process leads to a smaller increase in output compared to previous additions of the same input. In other words, as more and more units of the input are added, the marginal output of each additional unit begins to decrease, ultimately leading to a point where total output may begin to decrease as well. This phenomenon is commonly observed in short-run production processes and can be caused by a variety of factors such as limited resources or inefficient production techniques.