Question

If an object of 5 cm height is kept at a distance of 30 cm in front of a convex lens of focal length 20 cm, what would be the position and size of image formed?
(a) +60 cm, -10 cm (c) -60 cm, +10 cm

(b) +10 cm, - 30 cm (d) -10 cm, -6 cm​

Answer 1

Answer:

hey

Explanation:

Height of object, h  

o

​

=5cm, object distance u=−30cm, focal length f=−20cm  

Now, from mirror formula :  

f

1

​

=  

v

1

​

+  

u

1

​

 

v

1

​

=  

f

1

​

−  

u

1

​

 

     =  

20

−1

​

+  

30

1

​

 

     =−  

60

1

​

 

v=−60cm - image distance  

Magnification, m=−  

u

v

​

=−  

−30

−60

​

=−2

Size of image, h  

i

​

=m(h  

o

​

)=−2(5)=−10 cm

Answer 2

Answer:

Hello friend your answer is option number (a)