ANS:C - 120

The usual value of resistance suitable for a wire resistance strain gauge is 120 ohms. Explanation: Wire resistance strain gauges are commonly used in measuring strain, which is the deformation of a material in response to applied stress. These strain gauges typically consist of a fine wire (often made of an alloy such as constantan) arranged in a grid pattern on a flexible substrate. The resistance of a wire resistance strain gauge is typically selected to be around 120 ohms. This value strikes a balance between sensitivity to strain and practical considerations such as electrical noise, temperature effects, and signal conditioning requirements. While strain gauges with other resistance values exist, such as 20 ohms or 80 ohms, 120 ohms is a common standard value used in many applications. This value provides a good compromise between sensitivity and compatibility with signal conditioning equipment.