assembler dc field yoke Interview Questions and Answers

0
100 Interview Questions and Answers: DC Field Yoke

  1. What is a DC field yoke?

    • Answer: A DC field yoke is the outer frame of a DC machine (motor or generator) that provides a path for the magnetic flux produced by the field windings. It's typically made of ferromagnetic material with high permeability to minimize magnetic reluctance and maximize flux density.

  2. What is the primary function of the field yoke?

    • Answer: Its primary function is to provide a low-reluctance path for the magnetic flux generated by the field windings, creating a strong magnetic field within the air gap where the armature rotates.

  3. What materials are typically used for DC field yokes?

    • Answer: Cast steel, rolled steel, or sometimes even laminated steel are commonly used due to their high permeability and saturation characteristics.

  4. Why is high permeability important in the field yoke material?

    • Answer: High permeability ensures that most of the magnetic flux generated by the field windings flows through the yoke and into the air gap, minimizing flux leakage and maximizing the machine's efficiency and torque/power output.

  5. How does the shape of the field yoke affect its performance?

    • Answer: The shape is designed to optimize the distribution of the magnetic flux, minimizing leakage and maximizing the flux density in the air gap. A properly shaped yoke helps to improve the machine's performance and reduce losses.

  6. What is the role of the field yoke in minimizing magnetic saturation?

    • Answer: By providing a large cross-sectional area, the field yoke helps to prevent magnetic saturation, allowing higher field currents and stronger magnetic fields without significant performance degradation.

  7. How does the field yoke contribute to the mechanical strength of the DC machine?

    • Answer: The yoke forms the outer structural frame of the machine, providing significant mechanical strength and rigidity to support the other components, such as the poles and armature.

  8. Explain the relationship between the field yoke and the field poles.

    • Answer: The field poles are attached to the field yoke. The yoke provides a return path for the magnetic flux from the poles, completing the magnetic circuit.

  9. What are some common manufacturing methods for DC field yokes?

    • Answer: Casting, forging, and machining are commonly used to manufacture field yokes, depending on the size and complexity of the machine.

  10. How does the size of the field yoke affect the machine's performance?

    • Answer: A larger yoke typically allows for a stronger magnetic field, potentially leading to higher torque and power output, but also increased weight and cost.

  11. How is the field yoke protected against corrosion?

    • Answer: Often, a protective coating like paint or varnish is applied to prevent corrosion, especially in humid or harsh environments.

  12. What are the consequences of a damaged or cracked field yoke?

    • Answer: A damaged yoke can lead to significant magnetic flux leakage, reduced machine efficiency, and even potential safety hazards.

  13. How is the field yoke inspected for defects?

    • Answer: Visual inspection, magnetic particle inspection, and ultrasonic testing are common methods to check for cracks or other defects.

  14. What is the difference between a cast steel and a rolled steel field yoke?

    • Answer: Cast steel yokes are produced by casting molten steel into a mold. Rolled steel yokes are made by rolling steel into the desired shape. Cast steel offers greater design flexibility, while rolled steel can be more cost-effective for simpler shapes.

Thank you for reading our blog post on 'assembler dc field yoke Interview Questions and Answers'.We hope you found it informative and useful.Stay tuned for more insightful content!