Which of the listed conditions might...

Question 1 / 270705eccefa4bacbc34ba4d4853d

Question 1 of 270705eccefa4bacbc34ba4d4853d

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars?

Question 1 of 27070

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars?

🔍 Key Concepts

• Function of the commutator and brushes in a DC machine • How brush material and contact affect commutator surface wear • Difference between electrical faults (open/ground) and mechanical/abrasive wear causes

💭 Think About

• Ask yourself which option most directly changes the physical contact and rubbing conditions between the brushes and the commutator bars. • Consider which condition would cause increased friction, heat, or abrasion at the commutator surface, rather than just an electrical fault. • Think about what happens if the material of the brushes is too hard, too soft, or not matched to the commutator design.

✅ Before You Answer

• Identify which choice deals with brush material or contact pressure rather than just wiring or grounding issues. • Eliminate any options that mainly describe electrical continuity problems without directly increasing sliding wear on the commutator surface. • Verify which condition would most likely cause excessive mechanical wear on the copper bars themselves over time.

Question 1 of 27070

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars?

A grounded commutator bar

Using improper grade of carbon brushes

Aligning the front and rear mica V-rings improperly

An open circuit in the armature

Question 1 / 270705eccefa4bacbc34ba4d4853d

Question 1 of 270705eccefa4bacbc34ba4d4853d

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars?

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Question 1 of 27070

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars?