Ans. As per Railway Recruitment Board manual of 2015, candidates 10 times the notified vacancies are to be called for 2nd Stage CBT for Non Technical Popular Categories (NTPC). This is to ensure that the number is limited to the extent that the same can be managed in one or limited shifts to avoid extensive normalization as well as to ensure that adequate candidates are available for deciding the merit after initial screening done through 1st Stage CBT. This same was followed in earlier Centralized Employment Notification (CEN) 02/2010 (for Graduates) and CEN 04/2010 (for 10+2) where candidates 10 times the vacancies were called for 2nd Stage CBT before increasing the same to 15 times for CEN 03/2015 (Graduates)