Transducers and measured quantities — match each sensor to what it measures most directly List I (Transducer) A. LVDT (Linear Variable Differential Transformer) B. Bourdon tube gauge C. Strain gauge (with bridge) D. Thermistor List II (Quantity measured) 1. Pressure 2. Temperature 3. Displacement 4. Stress (via calibrated strain)

Introduction / Context:
Instrumentation design begins with selecting the right transducer for the measurand. This question aligns common sensors with the primary physical quantity they measure or are routinely used to infer in engineering practice.

Given Data / Assumptions:

• LVDT outputs a differential voltage proportional to core displacement.
• Bourdon gauges convert pressure to tube deflection and pointer motion.
• Strain gauges sense strain; with Young’s modulus they infer stress.
• Thermistors change resistance with temperature.

Concept / Approach:
Match each device to the measurand most directly or most commonly associated in calibrated systems: LVDT → displacement; Bourdon tube → pressure; strain gauge bridges → strain which maps to stress; thermistor → temperature.

Step-by-Step Solution:

Verification / Alternative check:
Manufacturer datasheets list LVDT linear ranges in mm; Bourdon gauges are graded in pressure units; strain gauge applications include stress analysis; thermistor R–T curves enable thermometer design.

Why Other Options Are Wrong:

• Pairings that put thermistors with pressure or LVDTs with temperature contradict sensor physics.
• Strain gauges do not directly measure temperature or pressure; they measure strain, used to compute stress.

Common Pitfalls:
Assuming the gauge factor device reads “force”; proper signal conditioning and mechanical design are required to relate strain to stress/force.

Final Answer:
A-3, B-1, C-4, D-2