A real image of equal size is obtained at a distance of 48 cm from the lens. The type of the lens and its focal length is:

This question was previously asked in
RRB Group D 13 Sept 2022 Shift 2 Official Paper
View all RRB Group D Papers >
  1. convex lens of focal length 48 cm
  2. concave lens of focal length of 48 cm
  3. convex lens of focal length 24 cm
  4. concave lens of focal length 24 cm

Answer (Detailed Solution Below)

Option 3 : convex lens of focal length 24 cm
Free
RRB Group D Full Test 1
3.1 Lakh Users
100 Questions 100 Marks 90 Mins

Detailed Solution

Download Solution PDF

 The correct answer is Convex lens of focal length 24 cm.

Key Points

  • Convex mirrors, divergent lenses, and plane mirrors can never provide a true image.
  • A true image can only be created with a concave mirror and a converging lens if the item is farther distant from the focus point (i.e., more than one focal length away).
  • As the image is an equal size to that of the object. So, the object must be at 2F and also the image.
  • So, the focal length of the lens must be 24 cm.

asd

Latest RRB Group D Updates

Last updated on Jun 30, 2025

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

-> The RRB Group D Exam Date will be soon announce on the official website. Candidates can check it through here about the exam schedule, admit card, shift timings, exam patten and many more.

-> A total of 1,08,22,423 applications have been received for the RRB Group D Exam 2025. 

-> The RRB Group D Recruitment 2025 Notification was released for 32438 vacancies of various level 1 posts like Assistant Pointsman, Track Maintainer (Grade-IV), Assistant, S&T, etc.

-> The minimum educational qualification for RRB Group D Recruitment (Level-1 posts) has been updated to have at least a 10th pass, ITI, or an equivalent qualification, or a National Apprenticeship Certificate (NAC) granted by the NCVT.

-> This is an excellent opportunity for 10th-pass candidates with ITI qualifications as they are eligible for these posts.

-> The selection of the candidates is based on the CBT, Physical Test, and Document Verification.

-> Prepare for the exam with RRB Group D Previous Year Papers.

Get Free Access Now
Hot Links: teen patti - 3patti cards game teen patti master game teen patti master apk