LIVE Course for free

Rated by 1 million+ students
Get app now
JEE MAIN 2024
JEE MAIN 2025 Foundation Course
NEET 2024 Crash Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
509 views
in Physics by (71.7k points)
closed by
Calculate the distance at which an object should be placed in front of a convex lens of focal length 10 cm to obtain a virtual image of double its size.

1 Answer

0 votes
by (71.9k points)
selected by
 
Best answer
Correct Answer - `- 5 cm, -15 cm`
Here, `f = 10 cm`, object distance, `u = ?`
In a convex lens, as the image can be real as well as virtual, magnification, `m = v/u = +-2`
or `v = +-2u`
As `(1)/(f) = (1)/(v) - 1/u, 1/10 = 1/(+-2u) - 1/u = (+-1-2)/(2u)`
Thus, either `1/10 = - 1/(2u) or 1/10 = - 3/(2u)`
Clearly, `u = - 5 cm, u = -15 cm`

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...