DMRC Junior Engineer interview questions

I applied for JE(Electrical Branch) in september 2016 .Paper Was extremely easy consisting of technical + English + maths + general knowledge. In English focus on Reported speech topics . Paper is in February 2017 .I cleared written exam .Result was announced on 15 June 2017. Next stage is Interview and Document Verification held on 29-30 June 2017(for electrical) at Shastri Park ,Metro Bhawan . In Interview I was asked about: 1 Introduction about Myself 2 What is Harmonics? 3 What is VFD(Variable Frequency Drive) 4 What is power Transformer and how it is different from Distribution Transformer? 5 What is all day efficiency? 6 What is full form of wifi ? Be prepare about gap if there is any in your education. I have a gap of one year.

Ist round was the exam consist of 2 paper back to back just after 15 min. I was aspirant of mechaniacl engineering 1st paper -technical 120 que 2nd paper-english 60 que the 2nd round was interview .it just take 10 to 15 minutes 4 or 5 simple technical questions and 4 or 5 current affair questions were asked (Interview ratio was 1:3 that one selection for 3 interviews)