Which part is NOT included in an x-ray machine?

An x-ray machine typically consists of several integral components that work together to produce images. The tubehead is where x-rays are generated, while the control panel allows the operator to adjust settings such as exposure time and voltage. The exposure button is essential for starting the x-ray process.

The cooling system is not a standard part of every x-ray machine, especially in basic or dental x-ray setups. While some advanced x-ray machines may include a cooling system to prevent overheating during extended use, it is not a necessary component in all x-ray machines. Therefore, identifying the cooling system as the part that is not universally included correctly reflects its optional nature in the design of x-ray machines. This distinction helps clarify the essential components typically found in an x-ray system compared to those that may be added for specific uses or in higher-end models.