ANS:B - semiconductor

The most sensitive sensing element for strain measurement is the semiconductor strain gauge. Explanation:

• Semiconductor strain gauges are based on the principle of the piezoresistive effect, where the electrical resistance of a semiconductor material changes in response to mechanical strain.
• When subjected to mechanical strain, such as stretching or compression, the lattice structure of the semiconductor material deforms, altering the spacing between atoms and thereby affecting the material's electrical conductivity.
• Semiconductor strain gauges typically consist of a thin semiconductor film, such as silicon or germanium, deposited onto a flexible substrate. As the substrate deforms under applied strain, the resistance of the semiconductor material changes proportionally.
• Semiconductor strain gauges offer several advantages, including high sensitivity, wide measurement range, and excellent linearity.
• Compared to other types of strain gauges, such as wire resistance or foil strain gauges, semiconductor strain gauges typically exhibit higher sensitivity and lower thermal sensitivity, making them well-suited for precise strain measurement applications.