Answer:
Strain gauge:
Strain gauge is a sensor. It is use to measure the strain of the material with help of electric resistance. A strain gauge is attached to the work piece and when any change in dimensions of work piece occurs ,due to this electric resistance of strain gauge also changes. Then by using a proper electric circuit strain of a material can be measured. Depending upon the situations one or more than one strain gauges is attached to the work piece to measure the strain .
Use of strain gauges
1. To measure the stress of a structure.
2. Use for testing of ships ,vehicle ,dams etc.