Discussion
A traction drive using dc series motors controlled by resistance steps was superseded because
Answer: D
Correct answer: the resistance wasted a great deal of energy
Resistance control reduces the voltage reaching the armature by dissipating the surplus as heat, so at half speed roughly half the input is thrown away in the resistor bank. On a train stopping and starting constantly that is an enormous waste, and the heat itself is a problem in a confined space. Chopper control replaced it by varying the mean voltage with a switch that is either fully on or fully off, and so loses almost nothing. The series motor’s starting torque was never in question - it is what made it the traction motor of choice.
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