Answer / kaustav

active sensor r those which does not require any power source
where as passive sensors are those which require power source

Answer / tanvir

Active sensor are not required a power from out side to
operate thermocople is the example of that when the heat
produce its free end devlope a thermo EMF in mv and its
calibrate as per requirement.
and pesive sensor need a power from out side for operating.

Answer / meenakshi

wel,the main difference is that active sensor senses an
obstacle by sending and receiving signals for eg ultrasonic
sensors.whereas the passive sensors merely receives signal
for eg infrared sensors comes under this category.it juz
senses the obstacle by taking the heat signature of that
obstacle.

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