Question 120Electricity & Electronics - QMED
70% to passWhich of the listed colors properly describes a DC motor commutator when correct commutation is taking place?
ABurnished green
BChocolate brown
CBrick red
DShiny blue
AI Explanation
The correct answer is B) Chocolate brown. When proper commutation is taking place in a DC motor, the commutator segments should have a chocolate brown color. This is the result of the natural oxidation process on the copper commutator bars, which occurs when the brushes make proper contact and the motor is operating correctly. The other answer choices are incorrect because: A) Burnished green indicates excessive wear on the commutator, C) Brick red suggests excessive sparking and poor commutation, and D) Shiny blue is not a normal color for a properly functioning DC motor commutator.
Related Questions
Q206:In a three-phase, squirrel-cage type, induction motor, how is the primary rotati... Q501:When the operating handle of a molded-case circuit breaker is in the mid-positio... Q431:When charging lead-acid batteries, why should you reduce the charging rate as th... Q44:At a minimum threshold, how many milliamps of current through the body produces ... Q483:Which of the following methods should be used to test for an 'open' stator windi...
Ready to test your knowledge?
Take a Electricity & Electronics - QMED Practice ExamOfficial Resources