Optics Lens Refraction Quiz

Questions and Answers

What is the focal length formula derived from the lens maker's formula when $n_2 = n$ and $n_1 = 1$?

$1/f = (n - 1)(1/R_1 + 1/R_2)$

$1/f = (n - 1)(1/R_1 - 1/R_2)$ (correct)

$1/f = (n + 1)(1/R_1 + 1/R_2)$

$1/f = (n + 1)(1/R_1 - 1/R_2)$

Which equation represents the refraction at the surface ADC when light travels from medium $n_2$ to $n_1$?

$n_1 v - n_2 v = (n_2 - n_1) R_1$

$n_2 v - n_1 u = (n_2 - n_1) R_2$

$n_1 v - n_2 u = (n_1 - n_2) R_2$

$n_1 v - n_2 v = (n_1 - n_2) R_2$ (correct)

When the object is located at infinity, how does the final image position relate to the focal length?

$v = 0$

$v = 2f$

$v = f$ (correct)

$v = -f$

What is the relationship stated by the lens equation $1/v - 1/u = 1/f$?

<p>It relates both the object distance and image distance to the focal length.</p> Signup and view all the answers

How does the refractive index of the medium affect the design of lenses?

<p>Both A and C are correct.</p> Signup and view all the answers

Study Notes

Thin Lens and Refraction

A thin lens is made from a medium with refractive index ( n_2 ) placed in a medium with refractive index ( n_1 ).
Radii of curvature for the two surfaces of the lens are denoted as ( R_1 ) and ( R_2 ).
A point object ( O ) located on the principal axis emits light that refracts at two spherical surfaces, ABC and ADC, forming image ( I ) after traversing both surfaces.

Refraction Equations

The refraction at surface ABC is described by the equation: [ n_2 v - n_1 u = (n_2 - n_1) R_1 ]
For the surface ADC, light refracts from medium ( n_2 ) to ( n_1 ), represented by: [ n_1 v - n_2 v = (n_1 - n_2) R_2 ]
Adding these two equations leads to a general relation: [ \frac{1}{v} - \frac{1}{u} = (n_2 n_1 - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right) ]

Lens with Object at Infinity

When the object is at infinity (( u = \infty )), the image forms at the focal point: [ v = f ]
Substituting into the previous equation gives: [ \frac{1}{f} - \frac{1}{\infty} = (n_2 n_1 - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right) ]

Lens Maker's Formula

For a lens with ( n_2 = n ) and ( n_1 = 1 ), the lens maker's formula simplifies to: [ \frac{1}{f} = (n - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right) ]
This formula is instrumental for manufacturers, allowing the design of lenses with specific focal lengths based on the glass's refractive index.

Lens Equation

The lens equation showcasing the relationship between object distance ( u ), image distance ( v ), and focal length ( f ) is given by: [ \frac{1}{v} - \frac{1}{u} = \frac{1}{f} ]
This highlights the correlation among object position, image position, and focal length in optical systems.

Description

Test your understanding of lens optics with this quiz focusing on the principles of refraction for thin lenses. It covers concepts such as radii of curvature and image formation from point objects. Perfect for students studying optics in physics.