JEE Advanced 2013Paper 1
- Exam
- JEE Advanced
- Year
- 2013
- Paper
- Paper 1
- Subject
- Physics
- Chapter
- Ray Optics
JEE Advanced 2013 · Paper 1 · Physics · Ray Optics
The image of an object, formed by a plano - convex lens at a...
The image of an object, formed by a plano - convex lens at a distance of 8 m behind the lens, is real and is one-third the size of the object. The wavelength of light inside the lens is times the wavelength in free space. The radius of the curved surface of the lens is
Options
- A1 m
- B2 m
- C3 m
- D6 m
Correct answer
C. 3 m
Step-by-step solution
V = 8m
Magnification =
u = -24
also μ = \dfrac{\text{c}}{{V}_{m}} = \dfrac{{λ}_{a}}{{λ}_{m}} = \dfrac{3}{2}
\dfrac{1}{\text{f}} = \left(μ - 1\right) \left(\dfrac{1}{{\text{R}}_{1}} - \dfrac{1}{{\text{R}}_{2 }}\right)
\dfrac{1}{\text{f}} = \left(μ - 1\right) \left(\dfrac{1}{\infty} - \dfrac{1}{- \text{R}}\right)
f = 2R
from lens formula
Magnification =
u = -24
also μ = \dfrac{\text{c}}{{V}_{m}} = \dfrac{{λ}_{a}}{{λ}_{m}} = \dfrac{3}{2}
\dfrac{1}{\text{f}} = \left(μ - 1\right) \left(\dfrac{1}{{\text{R}}_{1}} - \dfrac{1}{{\text{R}}_{2 }}\right)
\dfrac{1}{\text{f}} = \left(μ - 1\right) \left(\dfrac{1}{\infty} - \dfrac{1}{- \text{R}}\right)
f = 2R
from lens formula