In general, what can cause D.C. propulsion...

Question 1 / 270705eccefa3bacbc34ba4d4809b

Question 1 of 270705eccefa3bacbc34ba4d4809b

In general, what can cause D.C. propulsion motor brush sparking to be excessive?

Question 1 of 27070

In general, what can cause D.C. propulsion motor brush sparking to be excessive?

🔍 Key Concepts

• DC propulsion motor brushes and how they make contact with the commutator • What good commutator condition looks like (color, roundness, surface) • How brush grade, spring pressure, and position affect sparking

💭 Think About

• Think about which choice describes faults or problems rather than normal or even desirable conditions in a DC motor • Ask yourself: which items would a motor technician deliberately aim for when setting up a motor, and which would they try to correct? • Consider how poor contact between brushes and the commutator could lead to arcing or sparking—what specific factors would interfere with smooth contact?

✅ Before You Answer

• Identify which answers describe proper/normal commutator condition versus abnormal/faulty condition • Check which factors directly affect brush contact pressure, material behavior, and alignment with the commutator • Eliminate any option that sounds like a desired design feature rather than a cause of trouble

Question 1 of 27070

In general, what can cause D.C. propulsion motor brush sparking to be excessive?

incorrect brush grade, pressure or position

a concentric commutator

a dark chocolate colored commutator

brushes positioned in the neutral plane