What can cause excessive sparking of D.C....

Question 1 / 270705eccefa3bacbc34ba4d48066

Question 1 of 270705eccefa3bacbc34ba4d48066

What can cause excessive sparking of D.C. motor brushes? Improperly seated brushes Improperly set brush rigging

Question 1 of 27070

What can cause excessive sparking of D.C. motor brushes? Improperly seated brushes Improperly set brush rigging

🔍 Key Concepts

• Brush-to-commutator contact in a D.C. motor • Effect of brush position (brush rigging) on commutation and arcing • Mechanical vs. electrical causes of sparking at the brushes

💭 Think About

• Think about what happens if the brush face does not match the curvature of the commutator—how does that affect current density and sparking? • Consider how moving the brush rigging slightly ahead or behind the neutral plane affects the current reversal in the armature coils. • Ask yourself: can each listed condition, by itself, reasonably disturb commutation enough to create visible sparking?

✅ Before You Answer

• Verify whether poor contact area between brush and commutator would increase or decrease local heating and arcing. • Check if incorrect brush angle or position relative to the neutral plane is known to cause commutation problems and sparking. • Confirm whether each of the two listed issues is independently capable of causing sparking, or if one is harmless by itself.

Question 1 of 27070

What can cause excessive sparking of D.C. motor brushes? Improperly seated brushes Improperly set brush rigging

I only

II only

Either I or II

Neither I nor II