Discussion
Brush contact drop in a dc machine is usually taken as about
Answer: B
Correct answer: one volt per brush
The contact drop of a carbon brush is roughly one volt and, importantly, is nearly independent of the current density, so the brush loss is taken as \( I_a \) times about two volts for the pair. On a 240 V machine that is under one per cent, but on a low-voltage machine it can be a significant fraction of the output, which is why metal-graphite brushes are used there.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development