Online UPS requires

This question was previously asked in
ALP CBT 2 Electronic Mechanic Previous Paper: Held on 21 Jan 2019 Shift 2
View all RRB ALP Papers >
  1. Only battery
  2. Both rectifier and inverter
  3. Only rectifier
  4. Only inverter

Answer (Detailed Solution Below)

Option 2 : Both rectifier and inverter
Free
General Science for All Railway Exams Mock Test
2.1 Lakh Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF

Online UPS:

  • Online UPS are also known as double conversion UPS or true online UPS. There are two stages in its operation.
  • In the first stage, the mains AC is rectified to DC. There is a DC bus. DC bus can get power from both the DC battery and DC obtained by rectifying the mains AC.
  • In the second stage, DC power available from DC bus is converted to AC by the inverter and this AC is connected to the output.
  • In normal operation, output comes from mains AC via rectifier and inverter.
  • When mains AC fail, output comes from DC battery via an inverter. The changeover is instantaneous. There is no power transfer switch and hence no time delay.
  • When mains AC is available normal operation continues and the rectifier recharges the battery.
  • A bypass switch connects mains AC directly to the output in case there is some problem with the UPS.
Latest RRB ALP Updates

Last updated on Jun 11, 2025

-> The RRB NTPC Admit Card 2025 has been released on 1st June 2025 on the official website.

-> The UPSC Prelims Result 2025 and UPSC IFS Result 2025 has been released @upsc.gov.in

-> Railway Recruitment Board activated the RRB ALP application form 2025 correction link, candidates can make the correction in the application form till 31st May 2025. 

-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.

-> The Railway Recruitment Board (RRB) has released the official RRB ALP Notification 2025 to fill 9,970 Assistant Loco Pilot posts.

-> The official RRB ALP Recruitment 2025 provides an overview of the vacancy, exam date, selection process, eligibility criteria and many more.

->The candidates must have passed 10th with ITI or Diploma to be eligible for this post. 

->The RRB Assistant Loco Pilot selection process comprises CBT I, CBT II, Computer Based Aptitude Test (CBAT), Document Verification, and Medical Examination.

-> This year, lakhs of aspiring candidates will take part in the recruitment process for this opportunity in Indian Railways. 

-> Serious aspirants should prepare for the exam with RRB ALP Previous Year Papers.

-> Attempt RRB ALP GK & Reasoning Free Mock Tests and RRB ALP Current Affairs Free Mock Tests here

Get Free Access Now
Hot Links: teen patti lucky teen patti all games teen patti star