The image of an object formed by a lens is of magnification -1. If the distance between the object and it's image

Asked by durgeshsri8080 | 31st Jul, 2020, 10:45: PM

Expert Answer:

I n space c a s e space o f space l e n s
m equals v over u
i f space m a g n i f i c a t i o n space i s space minus 1 space i t space s h o w s space t h a t space i m a g e space a n d space o b j e c t space h a s space e q u a l space s i z e space f o r space t h a t space t h e space o b j e c t space m u s t space b e space p l a c e d space a t space t h e space 2 F space o f space c o n v e x space l e n s space
a n d space i f space t h e space d i s tan c e space b e t w e e n space t h e space i m a g e space a n d space t h e space o b j e c t space i s space 60 c m space t h e n space
t o t a l space d i s tan c e space 4 F equals 60
F equals 15 c m
N o w space i f space t h e space o b j e c t space i s space m o v e d space 20 c m space c l o s e r space t h a n space
o b j e c t space p o s i o n space w o u l d space b e space
I n i t i a l space o b j e c t space p o s i t i o n space u equals negative 30 c m
u equals negative 10 c m
f equals 15 c m
L e n s space f o r m u l a space
1 over f equals 1 over v minus 1 over u
1 over 15 equals 1 over v minus fraction numerator 1 over denominator negative 10 end fraction
1 over v equals 1 over 15 minus 1 over 10
1 over v equals fraction numerator 2 minus 3 over denominator 30 end fraction
v equals negative 30 c m
Image formed is virtual errect and larger than the object

Answered by Utkarsh Lokhande | 3rd Aug, 2020, 01:20: PM