3B Scientific SEK Optics User Manual

ELWE

Experimental Equipment Set for Students (SEG)

Optics

84 78 000

Reproduction is allowed only for use with ELWE-equipment.

 2002 ELWE Lehrgerätebau Klingenthal GmbH, Steinfeldstraße 5, 08248 Klingenthal, Germany

Tel. +49 37467 597-0 • Fax +49 37467 597-20

Printed in Germany by ELWE - Lehrsysteme GmbH

GB

84 78 000.32 08/02

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OPContents

OP 1 Diffusion of light

OP 1.1 Diffusion of light, pencil of rays and light beam

OP 1.2 Light transmission

OP 1.3 Shadows

OP 1.4 Half-shadow and complete shadow

OP 2 Reflection

OP 2.1 Reflection on a plane mirror

OP 2.2 Collecting light with a concave mirror

OP 2.3 Reflection and beam paths on a concave mirror

OP 2.4 Reflection and beam paths on a convex mirror

OP 2.5 Images on a plane mirror

OP 3 Refraction

OP 3.1 Refraction for the transition from air to glass

OP 3.2 Law of refraction, determining the refractive index

OP 3.3 Refraction for the transition from glass to air

Reproduction is allowed only for use with ELWE-equipment.

OP 3.4 Critical angle for total reflection

OP 3.5 Light curve on a plane-parallel plate

OP 3.6 Light curve on a prism

OP 3.7 Total reflection on a prism

OP 4 Lenses

OP 4.1 Collecting light on an focusing lens

OP 4.2 Refraction on a focusing lens / focal length

OP 4.3 Path of rays through a focusing lens

OP 4.4 Refraction on a dispersing lens

OP 4.5 Path of rays through a dispersing lens

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OPContents

OP 4.6 Path of rays through a combination of lenses

OP 4.7 Developement of images on focusing lenses

OP 4.8 Lens equation and equation for the image magnification

OP 4.9 Image defects

OP 5 Eye

OP 5.1 Generation of images in the eye

OP 5.2 Short-sightedness and its correction

OP 5.3 Farsightedness and its correction

OP 6 Optical equipment

OP 6.1 Photo camera

OP 6.2 Still projector

OP 6.3 Microscope

OP 6.4 Dutch telescope

OP 6.5 Astronomical telescope

OP 7 Colours

OP 7.1 Colour splitting with a prism

OP 7.2 Recombination of spectral colours

OP 7.3 Additive mixture of colours

Reproduction is allowed only for use with ELWE-equipment.

Equipment list

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 1.1Diffusion of Light, Pencil of Rays and Light Beam

Exercise

Examine how light diffuses!

What do we need?

1 Optical lamp

with power supply unit

1 Base plate

1 Three-slot aperture

1 Mask

Conducting the experiment

1. Attach the mask to the base plate!

Reproduction is allowed only for use with ELWE-equipment.

2. Place the optical lamp on the left side of the base plate, so that the light emerges conically to the right!

3. Sketch the edges of the beam of light on the mask!

4. Hatch the illuminated area with a coloured pen!

5. Insert the three-slot aperture into the aperture holder!

6. Draw the three narrow beams of light as lines!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 1.1Diffusion of Light, Pencil of Rays and Light Beam

Analysis

Sketch

Result

1. The light diffuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. A very narrow beam of light is called a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reproduction is allowed only for use with ELWE-equipment.

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 1.2Light Transmission

Exercise

Examine how materials react when exposed to light!

What do we need?

1 Optical lamp

with power supply unit

1 Base plate

1 Screen

1 Plexiglass pane

1 Mask

additionally required:

1 Glass pane

1 Transparent foil

1 Transparent paper

1 Mat glass pane

1 Book

Conducting the experiment

Reproduction is allowed only for use with ELWE-equipment.

1stexperiment

1. Attach the mask to the base plate!

2. Place the optical lamp on the left side of the base plate, so that the light emerges conically to the right!

3. Place the screen onto the base plate as marked on the mask!

4. Put the transparent plate in front of the light source and examine how much light is transmitted!

5. Use further materials and examine how they transmit light!

6. Arrange the materials and record them in table 1 according to how they react!

nd

2

experiment

1. Cut out six equal squares of transparent paper (5 cm x 5 cm each)! Draw a match-stick man on one square!

2. Insert the square with the match-stick man into the aperture holder!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 1.2Light Transmission

3. Look into the light and check whether you can still see the match-stick man!

4. Put two, then three, then four and finally five squares of transparent paper in front of the match-stick man!

5. Check how much light is transmitted! Enter the test results in table 2!

Analysis

Table 1 Light transmission

Light is transmitted Some light is transmitted No light is transmitted

Table 2 Light transmission as a function of thickness

Light transmission

Number of paper squares

(very good / good / less satisfactory /

little / none)

Result

1. There are materials that . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .light,

they are called . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. There are materials that . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .,

they are called . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reproduction is allowed only for use with ELWE-equipment.

3. There are materials that . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .,

they are called . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4. The translucence of light is a function of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 1.3Shadows

Exercise

Examine how shadows develop and under what conditions shadows are large or small!

What do we need?

1 Optical lamp

with power supply unit

1 Base plate

1 Shadow object

1 Screen

1 Mask

additionally required:

3 Sheets of white paper, 17 cm x 13 cm

1 Eraser

1 Sharpener

1 Adhesive tape

1 Ruler

Conducting the experiment

1stexperiment

Reproduction is allowed only for use with ELWE-equipment.

1. Attach the mask to the base plate!

2. Place the optical lamp on the left side of the base plate, so that the light emerges conically to the right!

3. Place the screen on the right side of the base plate!

4. Put the shadow object right in front of the screen as marked on the mask!

5. Measure the height and width of the shadow object and the height and width of the shadow! Enter the values in table 1!

6. Slowly move the shadow object a few centimetres towards the lamp and observe how the shadow changes! Discribe the result!

7. Put the shadow object back in front of the screen! Now hold the screen at different distances to the shadow object and observe how the shadow changes! Discribe the result!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 1.3Shadows

2ndexperiment

1. Attach a piece of white paper to the screen!

2. Put the screen back to the end of the base plate and the cylinder as close to the screen as possible!

3. Sketch the shape of the shadow on the white paper!

4. First place the sharpener and then the eraser on the same spot and sketch each shape of the shadow on a piece of white paper! Compare the shape of the shadows with the shape of the object!

Analysis

Table

Height of the

shadow object

Length of the

shadow object

Height of the shadow Length of the shadow

Observations when the shadow object is moved towards the optical light:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Observations when the screen is moved away from the shadow object:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Result

Reproduction is allowed only for use with ELWE-equipment.

1. Behind a . . . . . . . . . . . . . . . . . . . . . . . . object a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . develops.

2. The shadow increases, when . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. The dimension of the shadow depends on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4. The shape of the shadow depends on. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 1.4Half-Shadow and Complete Shadow

Exercise

Examine the shape of the shadow when the object is illuminated by two light sources!

What do we need?

1 Base plate

1 Screen

2 Tea lights

1 Shadow object

1 Mask

additionally required:

1 Sheet of white paper, 17 cm x 13 cm

Conducting the experiment

1. Attach the mask to the base plate!

2. Put two tea lights and the shadow object onto the base plate as marked on the mask! Attach the white paper to the screen and place the screen on the right side of the base plate!

Reproduction is allowed only for use with ELWE-equipment.

3. Carefully light the first tea light! Observe and draw the shadow behind the shadow object! Use the given data for sketch 1!

4. Mark in sketch 1 where a shadow develops when just one tea light is lit!

5. Light the second tea light! Observe the shadow behind the shadow object!

6. Cross all shadows with different shades of grey on the paper attached to the screen!

7. Construct the beam development! Use the given data for sketch 2!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 1.4Half-Shadow and Complete Shadow

Analysis

Sketch 1

Shadow when one tea light is lit:

Tea light

Sketch 2

Forming a shadow image with two tea lights:

Tea lights Cylinder

Cylinder

Screen

Reproduction is allowed only for use with ELWE-equipment.

Result

1. Features of the shadow when one tea light is lit:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. Features of the shadow when both tea lights are lit:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ELWE

Physical experiments for education in natural science and engineering

3 SEG - OP 1.4Half-Shadow and Complete Shadow

3. When the shadow object is illuminated by two light sources, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

develops behind the shadow object.

Reproduction is allowed only for use with ELWE-equipment.

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 2.1Reflection on a Plane Mirror

Exercise

Examine the incident light on a plane reflecting surface!

What do we need?

1 Optical lamp

with power supply unit

1 Base plate

1 Universal mirror

1 Single-slot aperture

1 Screen

1 Mask

additionally required:

1 Triangle with right angle

1 Coloured pen

Conducting the experiment

1. Attach the mask to the screen!

2. Place the optical lamp on the left side of the base plate, so that light emerges parallel to the right!

Reproduction is allowed only for use with ELWE-equipment.

3. Place the screen in front of the optical lamp!

4. Insert the single-slot aperture into the aperture holder!

5. Place the universal mirror on the screen as marked on the mask!

6.

Adjust an angle of incidence α = 30° by changing the position of the lamp! Draw the incident and the reflected beam on the mask!

7. Draw the axis of incidence! Measure the angle of incidence and the angle of reflection! Enter the values in the table!

8. Turn the lamp a little and adjust a different angle of incidence! Draw the incident and the reflected beam. Draw the axis of incidence and measure the angle of incidence and the angle of reflection! Use a coloured pen! Enter the measured values in the table!

9. Turn the lamp a little further! Again draw the beams and the axis of incidence and measure the angles of incidence and reflection!

10. Compare the angle of incidence to the angle of reflection and describe the result!

11. Name practical applications for the use of reflection! Give one example!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 2.1Reflection on a Plane Mirror

Analysis

Table

Angle of incidence α Angle of reflection α‘

Result

1. The law of reflection says:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. Practical applications for the use of reflection:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. Explanation of an example:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reproduction is allowed only for use with ELWE-equipment.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 2.2Collecting Light with a Concave Mirror

Exercise

Examine the incident light on a bent reflecting surface (concave mirror)!

What do we need?

1 Optical lamp

with power supply unit

1 Base plate

1 Universal mirror

1 Screen

1 Three-slot aperture

1 Mask

additionally required:

1 Ruler

1 Coloured pen

Conducting the experiment

1. Attach the mask to the screen!

Reproduction is allowed only for use with ELWE-equipment.

2. Place the optical lamp on the left side of the base plate, so that the light emerges parallel to the right!

3. Place the screen in front of the optical lamp!

4. Place the mirror on the screen and bend it as marked on the mask!

5. Insert the three-slot aperture into the aperture holder!

6. Observe the beam of light after hitting the concave mirror! Draw the beam of light on the mask!

7. Determine the distance between concave mirror and focal point and therefore the focal length!

8. Draw five incident beams of light and the respective reflected beams of light (sketch)!

9. Change the curvature of the concave mirror! Use a coloured pen to draw the concave mirror with the changed curvature on the mask! Repeat exercises 6 and 7!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 2.2Collecting Light with a Concave Mirror

Analysis

Radius of curvature of the concave mirror: . . . . . . . . . . . . . .

Focal length of the concave mirror: . . . . . . . . . . . . . . . . . . . .

Five incident beams of light and the respective reflected beams:

Sketch

optical axis

M

concave mirror

r

= 6.5 cm)

(

Result

1. On a concave mirror light is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. Incident light parallel to the optical axis is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . after reflection.

3. The curvature of the concave mirror affects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4. Three beams of light after reflection:

Reproduction is allowed only for use with ELWE-equipment.

A beam of light parallel to the optical axis is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. The focal length of the concave mirror depends upon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6. When the curvature increases, the . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 2.3Reflection and Beam Paths on a Concave Mirror

Exercise

Examine how selected beams of light are reflected on a concave mirror!

What do we need?

1 Optical lamp with power supply unit

1 Base plate

1 Universal mirror

1 Screen

1 Single-slot aperture

1 Three-slot aperture

1 Mask

additionally required:

1 Compasses

1 Ruler

Conducting the experiment

1. Attach the mask to the screen!

2. Place the optical lamp on the left side of the base plate, so that the light emerges parallel to the

Reproduction is allowed only for use with ELWE-equipment.

right!

3. Place the screen in front of the optical lamp!

4. Insert the three-slot aperture into the aperture holder!

5. Place the universal mirror on the screen and bend it as marked on the mask!

6. Determine the focal point with three parallel beams! Mark the focal point! Then draw the centre of the concave mirror! Enter the values for the focal length and the radius of the concave mirror in the table!

7. Replace the three-slot aperture by a one-slot aperture!

8. Generate a parallel beam close to the axis! Change the position of the optical lamp! Observe the parallel incident beam of light after it hit the concave mirror! Draw the incident and the reflected beam of light!

9. Repeat the experiment with a focal beam!

10. Repeat the experiment with a centre point beam!

11. Name possible applications for concave mirrors! Explain one application!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 2.3Reflection and Beam Paths on a Concave Mirror

Analysis

Table

Focal lengthfof the

concave mirror in cm

Radiusrof the

concave mirror in cm

Construct the concave mirror with the aid of the measured values and with the compass!

Draw the test results into your constructed concave mirror!

1. Parallel beam:

2. Centre point beam:

3. Focal beam:

Result

1. On a concave mirror light is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. Parallel beams are . . . . . . . . . . . . . . . . . . . .as . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. Focal beams are . . . . . . . . . . . . . . . . . . . . . as . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4. Centre point beams are . . . . . . . . . . . . . . . . as . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. Concave mirrors are used in the following technical appliances:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6. Description of an example:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reproduction is allowed only for use with ELWE-equipment.

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 2.4Reflection and Beam Paths on a Convex Mirror

Exercise

Examine how the light is reflected on the convex mirror!

What do we need?

1 Optical lamp

with power supply unit

1 Base plate

1 Universal mirror

1 Three-slot aperture

1 Mask

additionally required:

1 Compasses

1 Ruler

Conducting the experiment

1. Attach the mask to the screen!

Reproduction is allowed only for use with ELWE-equipment.

2. Place the optical lamp on the left side of the base plate, so that the light emerges parallel to the right!

3. Place the screen in front of the optical lamp! Insert the three-slot aperture into the aperture holder!

4. Place the universal mirror on the screen and bend it as marked on the mask!

5. Mark the position of the focal point. Mark it “F”!

6. Record your observations on the three parallel incident beams of light after the reflection! Draw the beams on the mask! Mark the point where the rear projections of the reflected beams cross the optical axis!

7. Bend the convex mirror as sketched! Transmit the beams onto the sketch!

8. Name practical applications for the use of convex mirrors!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 2.4Reflection and Beam Paths on a Convex Mirror

Analysis

Sketch

Result

incident beams of light:

optical axis

reflected beams of light:

convex mirror

r

= 6.5 cm)

(

1. On a convex mirror light is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. On a convex mirror the parallel beams are . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

as . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. Convex mirrors are used as: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reproduction is allowed only for use with ELWE-equipment.

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 2.5Images on a Plane Mirror

Exercise

Examine the features of images on a plane mirror!

What do we need?

1 Base plate

1 Plexiglass plate

2 Tea lights

1 Mask

additionally required:

1 Ruler

Conducting the experiment

1. Attach the mask to the base plate!

2. Place the Plexiglas plate onto the centre of the base plate as marked on the mask!

Reproduction is allowed only for use with ELWE-equipment.

3. Put a tea light in front of the plate (mask)! Observe the mirror image of the tea light!

4. Light the tea light and observe the mirror image! Record the features of the mirror image of the burning tea light!

5. Place the second non-burning tea light behind the Plexiglas plate where you see the mirror image! Record your observations and draw the position of the tea light on the mask!

6. Now move the burning tea light in front of the Plexiglass plate approx. 3 cm to the right! Observe the mirror image of the burning tea light!

7. Make a note of what you have to do to see the mirror image of the burning tea light at the same place as the non-burning tea light behind the pane!

8. Determine the distance of the tea light in front of the Plexiglas plate and behind the Plexiglas plate! Enter the measured values in the table! Mark the positions of the first and the second candle on the mask!

9. Name features of the mirror image!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 2.5Images on a Plane Mirror

Analysis

Table

Features

Measured values

Height of the two tea lights

Height of the mirror image of the non-burning tea light

Distance between Plexiglas plate and front tea light

Distance between Plexiglas plate and rear tea light

Changed position of the front tea light

Changed position of the rear tea light

Result

1. On the plane mirror . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . develops.

2. The images on a plane mirror have the following features:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reproduction is allowed only for use with ELWE-equipment.

ELWE

Physical experiments for education in natural science and engineering

1 SEG - OP 3.1Refraction for the Transition from Air to Glass

Exercise

Examine the way light reacts at the transition from air to glass!

What do we need?

1 Optical lamp

with power supply unit

1 Base plate

1 Screen

1 Semicircular glass object

(flat design)

1 Single-slot aperture

1 Mask

Conducting the experiment

1. Attach the mask to the screen!

2. Place the optical lamp on the left side of the base plate, so that the light emerges parallel to the right!

3. Place the screen in front of the optical lamp!

Reproduction is allowed only for use with ELWE-equipment.

4. Place the semicircular glass object onto the middle of the screen as marked on the mask!

5. Insert the single-slot aperture into the aperture holder on the optical lamp!

6. First, the light should hit the plane on the glass object along the optical axis! Observe the light when it passes the glass object1! Record your observations in the table!

7. Change the position of the optical lamp, so that the light hits the centre of the glass plate at an angle! Observe and record your observation!

8. Change the position of the optical lamp twice, so that the light hits the semicircular glass object at different angles! Observe and record your observations in the table!

9. If the path of light is reversible, it is possible to set up a statement on the way the light reacts at the transition from glass to air! Formulate the statement!

ELWE

Physical experiments for education in natural science and engineering

2 SEG - OP 3.1Refraction for the Transition from Air to Glass

Analysis

Table

Angle of incidence α

of the light

Observations for the transition from air to glass

Result

1. When transmitted from air to glass, the light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . with angles larger than 0°.

2. When the . . . . . . . . . . . . . . . . . . . . . . . . . . . . increases, the . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. When transmitted from glass to air, the light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reproduction is allowed only for use with ELWE-equipment.

ELWE

Physical experiments for education in natural science and engineering

3B Scientific SEK Optics User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1 SEG - OPContents