When the LED lights need a range of voltages to operate, Which of the following drivers is best suited for the job?

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. Constant frequency
  2. Constant Voltage
  3. Constant Impedance
  4. Constant Current

Answer (Detailed Solution Below)

Option 4 : Constant Current
Free
General Science for All Railway Exams Mock Test
2.1 Lakh Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF

Concept:

  • LED drivers are the driving force that provides and regulates the necessary power to make sure the LEDs operate in a safe and consistent manner. One important choice is that of choosing a constant current LED driver versus a constant voltage LED driver. 
  • Constant current LED drivers are designed for a designated range of output voltages and a fixed output current (mA). LEDs that are rated to operate on a constant current driver require a designated supply of current usually specified in milliamps (mA) or amps (A).

26 June 1

Constant voltage LED drivers are used for LEDs that require one stable voltage and have a current that is already regulated either via simple resistors or an internal constant current driver.

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

More Optical Sources and Detector Questions

Get Free Access Now
Hot Links: teen patti list teen patti master gold teen patti online game