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Assertion (A): Servomotors have heavier rotors and lower R/X ratio as compared to ordinary motors of similar ratings.
Reason (R): Servomotor should have smaller electrical and mechanical time constants for faster response.
  • a)
    Both A and R are true and R is the correct explanation of A
  • b)
    Both A and R are true but R is not correct explanation of A
  • c)
    A is true but R is false
  • d)
    A is false but R is true
Correct answer is option 'D'. Can you explain this answer?
Verified Answer
Assertion (A): Servomotors have heavier rotors and lower R/X ratio as ...
Explanation: Ac servomotors are essentially induction motor with low X/R ratio for the rotor which has very low inertia.
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Assertion (A): Servomotors have heavier rotors and lower R/X ratio as ...
Assertion (A): Servomotors have heavier rotors and lower R/X ratio as compared to ordinary motors of similar ratings.
Reason (R): Servomotor should have smaller electrical and mechanical time constants for faster response.

Explanation:
The given assertion states that servomotors have heavier rotors and lower R/X ratio compared to ordinary motors of similar ratings. The reason provided is that servomotors should have smaller electrical and mechanical time constants for faster response.

Understanding Servomotors:
- Servomotors are specialized motors designed for precise control of position, speed, and acceleration.
- They are commonly used in applications such as robotics, CNC machines, and automation systems.
- Servomotors provide high levels of accuracy, speed, and torque control, making them suitable for applications that require precise and rapid movements.

Heavier Rotors and Lower R/X Ratio:
- In order to achieve faster response and better control, servomotors are designed with certain characteristics different from ordinary motors.
- The rotor of a servomotor is typically heavier compared to an ordinary motor.
- The heavier rotor helps in providing better inertia, allowing the motor to quickly respond to changes in speed and position.
- This is especially important in applications where rapid acceleration and deceleration are required.

- The R/X ratio is the ratio of the resistance (R) to the reactance (X) of the motor.
- In servomotors, the R/X ratio is lower compared to ordinary motors.
- This is because a lower R/X ratio implies a higher reactance, which helps in reducing the electrical time constant of the motor.
- The electrical time constant represents the rate at which the current in the motor windings changes in response to a voltage change.
- By reducing the electrical time constant, servomotors can respond more quickly to changes in input signals, resulting in faster and more accurate control.

Evaluation of the Assertion and Reason:
- The assertion states the characteristics of servomotors (heavier rotors and lower R/X ratio) correctly.
- However, the reason provided does not correctly explain why servomotors have heavier rotors and lower R/X ratio.
- The reason suggests that servomotors have smaller electrical and mechanical time constants for faster response, but it does not directly explain why heavier rotors and lower R/X ratio are required for achieving smaller time constants.

Conclusion:
- In conclusion, the assertion (A) is true as servomotors do have heavier rotors and lower R/X ratio.
- However, the reason (R) is false as it does not correctly explain why servomotors have these characteristics.
- Hence, the correct answer is option 'D' - A is false but R is true.
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Assertion (A): Servomotors have heavier rotors and lower R/X ratio as compared to ordinary motors of similar ratings.Reason (R): Servomotor should have smaller electrical and mechanical time constants for faster response.a)Both A and R are true and R is the correct explanation of Ab)Both A and R are true but R is not correct explanation of Ac)A is true but R is falsed)A is false but R is trueCorrect answer is option 'D'. Can you explain this answer?
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Assertion (A): Servomotors have heavier rotors and lower R/X ratio as compared to ordinary motors of similar ratings.Reason (R): Servomotor should have smaller electrical and mechanical time constants for faster response.a)Both A and R are true and R is the correct explanation of Ab)Both A and R are true but R is not correct explanation of Ac)A is true but R is falsed)A is false but R is trueCorrect answer is option 'D'. Can you explain this answer? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Assertion (A): Servomotors have heavier rotors and lower R/X ratio as compared to ordinary motors of similar ratings.Reason (R): Servomotor should have smaller electrical and mechanical time constants for faster response.a)Both A and R are true and R is the correct explanation of Ab)Both A and R are true but R is not correct explanation of Ac)A is true but R is falsed)A is false but R is trueCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Assertion (A): Servomotors have heavier rotors and lower R/X ratio as compared to ordinary motors of similar ratings.Reason (R): Servomotor should have smaller electrical and mechanical time constants for faster response.a)Both A and R are true and R is the correct explanation of Ab)Both A and R are true but R is not correct explanation of Ac)A is true but R is falsed)A is false but R is trueCorrect answer is option 'D'. Can you explain this answer?.
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