Difficulty: Easy
Correct Answer: R is correct but A is wrong
Explanation:
Introduction / Context:Error detectors are essential in closed-loop position control systems, comparing the actual and desired values. Potentiometers are commonly used as position transducers due to their simplicity and linearity. This question tests knowledge of potentiometer applicability and limitations.
Given Data / Assumptions:
Concept / Approach:Assertion (A) claims potentiometers cannot be used — this is incorrect, as they are widely used. Reason (R) states resolution limits accuracy — this is true. However, the reason does not support the false assertion, so the correct choice is that R is correct while A is wrong.
Step-by-Step Solution:
Potentiometers produce an analog voltage proportional to shaft angle.They are commonly implemented in servomechanisms as error detectors.Resolution limits accuracy but does not make them unusable.Thus A is false; R is true.Verification / Alternative check:
Numerous industrial servosystems employ potentiometers successfully, proving A false.Why Other Options Are Wrong:
Option (a): Wrong because A is false. Option (b): Wrong for same reason. Option (c): Wrong as R is actually true. Option (e): Both being wrong contradicts known facts.Common Pitfalls:
Assuming resolution makes potentiometers entirely unsuitable; ignoring widespread use in low-cost servos.Final Answer:
R is correct but A is wrong
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