Suppose an acceptance rate is 30%, does this mean it is possible for political science could be 10%, psychology 20%, and biology 30%? Or does an acceptance rate cover all departments evenly?
No, it is just an overall acceptance rate. Colleges sometimes will publish data for separate schools like the school of engineering. But all the majors you mention are in the college of arts and sciences and often there are no caps for the separate majors within that. Many colleges just don’t admit by major to that extent. Depends on the college.
For individual departments (if admitted by major), it can be anything. For example, UIUC has a near 60% admission rate while CS has a single digit admission rate.