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Railways NTPC (Technical Ability) Metal Forming, Casting and Cutting Question Bank Metal Cutting

  • question_answer
    A grinding wheel of 150 mm diameter is rotating at 3000 rpm. The grinding speed is:

    A) \[7.5\,\pi \,\text{m/s}\]               

    B) \[15\,\pi \,\text{m/s}\]

    C) \[45\,\pi \text{m/s}\]                  

    D) \[450\,\pi \,\text{m/s}\]

    Correct Answer: A

    Solution :

    Grinding speed \[=\frac{\pi DN}{60}\] \[=\frac{\pi \times 0.15\times 3000}{60}\] \[=7.5\,\pi \,\text{m/s}\]


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