Where should an object be placed in front of a convex lens to get a real image of the size of the object?

(a) At the principal focus of the lens

(b) At twice the focal length

(c) At infinity

(d) Between the optical centre of the lens and its principal focus.

 

Answer

(b) At twice the focal length

 

Explanation

A convex lens produces an image of the same size 

when the object is placed at twice the focal length. 

This image is real and inverted.

Convex Lens Object at 2F - Teachoo.jpg

  1. Class 10
  2. Chapter 10 Class 10 - Light - Reflection and Refraction

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.