Which of the following devices has an accordion-type shape that reacts to pressure changes?

The correct answer is a device known as bellows, which indeed has an accordion-type shape and is specifically designed to react to pressure changes. Bellows are typically made from a flexible material that can expand and contract. When pressure changes occur, the bellows either compress or expand, allowing for the measurement of that pressure change. The accordion-like structure provides the necessary flexibility and responsiveness to accurately reflect the variations in pressure.

While other devices mentioned, such as diaphragm and Bourdon tubes, also measure pressure, they do not possess the same accordion-like shape characteristic of bellows. The diaphragm uses a flat or slightly curved membrane that deflects under pressure, while the Bourdon tube is a coiled or curved tube that straightens out when pressure is applied, which differs notably from the accordion design. These differences highlight why bellows are uniquely identified by their structure and functionality in response to pressure changes.