Question

Find the nature and power of a lens which forms a real and inverted image
of magnification -1 at a distance of 40 cm from its optical centre.

Answer 1

Answer:

#love.....

Explanation:

Given magnification m=−1 and object distance u=−20cm

We know magnification m=  

u

−v

​  

 

v=−mu=(−1)(−20)=20cm

Now from lens formula we have,

v

1

​  

−  

u

1

​  

=  

f

1

​  

 

20

1

​  

−  

20

−1

​  

=  

f

1

​  

 

f=10cm

Now powerp=  

f

1

​  

=  

100

10

​  

 

1

​  

=10 D