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GATE 2022 IN – Question 12

Sensors and Industrial Instrumentation · Displacement force and pressure measurement · 1 mark · Multiple choice

A pneumatic nozzle-flapper system is conventionally used to convert ________

  1. Small changes in flapper’s velocity to large changes in output temperature
  2. Small changes in flapper’s displacement to large changes in output temperature
  3. Small changes in flapper’s velocity to large changes in output pressure
  4. Small changes in flapper’s displacement to large changes in output pressure

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Correct answer: (D) Small changes in flapper’s displacement to large changes in output pressure

Explanation

A small flapper displacement changes the nozzle restriction and therefore its back pressure substantially. The device converts **small displacement changes to large pressure changes, D**, rather than directly sensing velocity or temperature.