A strain gauge is a device used to measure the amount of deformation or strain in an object when it is subjected to stress. It typically consists of a thin wire or foil arranged in a zigzag pattern, which is attached to the surface of the material being tested. When the material deforms, the strain gauge also deforms, causing a change in its electrical resistance. This change can be measured and correlated to the amount of strain experienced by the object. Strain gauges are commonly used in various fields, including engineering, construction, and aerospace, to monitor the structural integrity of materials and components. They can help detect potential failures by providing real-time data on stress levels. Applications include testing bridges, aircraft wings, and even medical devices, making them essential tools in ensuring safety and reliability in many industries.