Assertion–Reason (Control Systems): Assertion (A): Potentiometers cannot be used as error detectors in position control systems. Reason (R): The resolution of a potentiometer places an upper limit on its accuracy.

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:

• Potentiometer converts angular displacement into proportional voltage.
• Finite resolution and wear affect accuracy but do not preclude usage.
• Position control requires continuous error detection capability.

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:

Verification / Alternative check:

Why Other Options Are Wrong:

Common Pitfalls:

Final Answer: