Discussion
The induction motor will be operated in the reverse plugging mode if the slip is ______.
Answer: B
The slip of an induction motor is \(s = (N_s - N)/N_s\). In plugging (reverse rotation of the field) the supply phase sequence is reversed, so the field rotates at \(-N_s\) while the rotor is still turning forwards at \(N\).
\[ s = \frac{-N_s - N}{-N_s} = 1 + \frac{N}{N_s} \]
With \(N\) between 0 and \(N_s\), the slip lies between 1 (at standstill) and 2 (at synchronous speed). A slip of zero is synchronous speed, a slip between 0 and 1 is normal motoring (and up to 0.1 the usual operating range), so the answer is between 1 and 2, option B.
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