Answer :

(a) Given

Object distance (u) = -100cm


Focal length (f) = 50cm


Image distance = v


By lens formula;






v=100cm


Hence the image is formed at 100 cm behind the lens.


Object distance (u) = -100cm


Focal length (f) = -25cm


Image distance = v


By lens formula;






v =


v= -20cm


Hence the image is formed at 20cm in front of the lens.


(b) For 1st case


Object distance (u) = -100cm


Image distance (v) = 100cm.


By Magnification Formula


Magnification (m) =


Magnification =


Therefore, Magnification for the 1st case is -1. The negative sign means the image is real and inverted.


For 2nd case


Object distance (u) = -100cm


Image distance (v) = -20cm.


By Magnification Formula


Magnification (m) =


Magnification =


Therefore, Magnification for 2nd case is 0.2. The positive sign means the image is erect and virtual.


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Reflection of light-2Reflection of light-2Reflection of light-238 mins
Reflection of Light-1Reflection of Light-1Reflection of Light-144 mins
Refraction of light-1Refraction of light-1Refraction of light-125 mins
Light - 2Light - 2Light - 243 mins
History - Concept and QuestionsHistory - Concept and QuestionsHistory - Concept and Questions57 mins
Corrosion: Types, Pros and ConsCorrosion: Types, Pros and ConsCorrosion: Types, Pros and Cons41 mins
Trigo Marathon Part 2Trigo Marathon Part 2Trigo Marathon Part 245 mins
Arithmetic Progression and 'nth' Term of APArithmetic Progression and 'nth' Term of APArithmetic Progression and 'nth' Term of AP55 mins
Revision on Substitution and  Elimination MethodRevision on Substitution and  Elimination MethodRevision on Substitution and Elimination Method44 mins
Trigo Marathon Part 1Trigo Marathon Part 1Trigo Marathon Part 146 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :

If the image formXam idea - Science

The image of an oAll In One Science

List the sign conAll In One Science

An object is keptAll In One Science

A 2.0 cm tall objTogether With Science

A 5 cm tall objecTogether With Science

<span lang="EN-USNCERT - Science Exemplar

Name the physicalLakhmir Singh & Manjit Kaur - Physics

The magnificationXam idea - Science

How far should anAll In One Science