Which of the following brushes can be used for high values of current density ?
Correct answer: A. Metal graphite brushes
- A. Metal graphite brushes
- B. Hard carbon brushes
- C. Electro-graphitic brushes
- D. Natural graphite brushes
Explanation
Metal-graphite brushes can carry high current density because the metallic content gives them low electrical resistance, while graphite provides lubrication and satisfactory commutation. Hard carbon and natural graphite brushes are generally used at lower current densities.
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