Crawling typically causes an induction motor to operate at a speed that is: 

This question was previously asked in
RRB JE EE 22 Apr 2025 Shift 2 CBT 2 Official Paper
View all RRB JE Papers >
  1. a fraction (e.g. 1/3) of synchronous speed
  2. double the synchronous speed
  3. equal to synchronous speed
  4. slightly below synchronous speed under full load

Answer (Detailed Solution Below)

Option 1 : a fraction (e.g. 1/3) of synchronous speed
Free
General Science for All Railway Exams Mock Test
2.1 Lakh Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF

Crawling in an induction motor

  • Crawling typically causes an induction motor to operate at a fraction (e.g., 1/3) of synchronous speed.
  • Crawling is a phenomenon in squirrel-cage induction motors caused by harmonics in the supply voltage or due to the motor's design.
  • This results in the motor getting "stuck" at around (1/3)th of the synchronous speed instead of accelerating to near synchronous speed.
  • It is commonly observed in motors with poor design or under heavy load during startup.
  • Crawling is often accompanied by high starting currents and can produce noticeable noise, further impacting the motor's operation and potentially damaging the surrounding environment. 
Latest RRB JE Updates

Last updated on Jun 7, 2025

-> RRB JE CBT 2 answer key 2025 for June 4 exam has been released at the official website.

-> Check Your Marks via RRB JE CBT 2 Rank Calculator 2025

-> RRB JE CBT 2 admit card 2025 has been released. 

-> RRB JE CBT 2 city intimation slip 2025 for June 4 exam has been released at the official website.

-> RRB JE CBT 2 Cancelled Shift Exam 2025 will be conducted on June 4, 2025 in offline mode. 

-> RRB JE CBT 2 Exam Analysis 2025 is Out, Candidates analysis their exam according to Shift 1 and 2 Questions and Answers.

-> The RRB JE Notification 2024 was released for 7951 vacancies for various posts of Junior Engineer, Depot Material Superintendent, Chemical & Metallurgical Assistant, Chemical Supervisor (Research) and Metallurgical Supervisor (Research). 

-> The selection process includes CBT 1, CBT 2, and Document Verification & Medical Test.

-> The candidates who will be selected will get an approximate salary range between Rs. 13,500 to Rs. 38,425.

-> Attempt RRB JE Free Current Affairs Mock Test here

-> Enhance your preparation with the RRB JE Previous Year Papers

Get Free Access Now
Hot Links: teen patti fun teen patti jodi teen patti online teen patti real cash game