## Book: HC Verma - Concepts of Physics Part 1

### Chapter: 18. Geometrical Optics

#### Subject: Physics - Class 11th

##### Q. No. 41 of Exercises

Listen NCERT Audio Books to boost your productivity and retention power by 2X.

41
##### A biconvex thick lens is constructed with glass (μ = 1.50). Each of the surfaces has a radius of 10 cm and the thickness at the middle is 5 cm. Locate the image of an object placed far away from the lens.

Biconvex lens with each surface has a radius (

Thickness of lens (t) = 5 cm

Refractive index of lens ==1.50

Position of object =

At first refraction occurs at A

By using lens equation:

Now, the second refraction occurs at B

Object distance =u= (30-5) = 25 cm (a virtual object)

So, (by using lens equation)

So, the image is formed 9.1 cm further from the 2nd surface of the lens.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65 .
66
67
68
69
70
71
72
73
74
75
76
77
78
79