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SarkariResultOutBMS · 2024

Previous Year Question

Read the following statement in the context of a DC motor position control system.Statement 1:Rate feedback is often provided to improve the damping of control system.Statement 2:The rate feedback is provided by a tachogenerator.Choose the correct option from the following:
  1. Both statement 1 and statement 2 are correct.
  2. Statement 1 is correct, but statement 2 is incorrect.
  3. Statement 2 is correct, but statement 1 is incorrect.
  4. Both statement 1 and statement 2 are incorrect.

Correct answer: A

Explanation

Rate feedback adds a signal proportional to motor speed and increases damping, reducing oscillation and overshoot. A tachogenerator produces a voltage proportional to shaft speed, so it is the conventional sensor used for rate feedback. Both statements are correct.

Formula

Vt=Ktω

Step-by-step solution

Tachogenerator Feedback explanatory diagram

Correct Answer

A — Both statement 1 and statement 2 are correct.

Statement-wise Analysis

Statement 1: True

Statement 2: True

Concept and Reasoning

Rate feedback adds a signal proportional to motor speed and increases damping, reducing oscillation and overshoot. A tachogenerator produces a voltage proportional to shaft speed, so it is the conventional sensor used for rate feedback. Both statements are correct.

Calculation / Key Relation

Vt=Ktω

Exam Takeaway

Tachogenerator = speed/rate feedback.

Common Mistake

Do not confuse rate feedback with position feedback.

Common mistake

Do not confuse rate feedback with position feedback.

Exam tip

Tachogenerator = speed/rate feedback.

Quick method

Tachogenerator = speed/rate feedback.