Difference between revisions of "PhET-Simulations-for-Physics/C2/Geometric-Optics/English"

From Script | Spoken-Tutorial
Jump to: navigation, search
(Created page with "'''Title of the script''': '''Installation of orca on Windows OS''' '''Author: '''Madhuri Ganapathi '''Keywords''': Orca, Windows 10 OS, zip files, Orca Forum, register, l...")
 
 
(5 intermediate revisions by the same user not shown)
Line 1: Line 1:
−
'''Title of the script''': '''Installation of orca on Windows OS'''
+
'''Title of the script''': Geometric Optics
  
 +
'''Author: Shraddha Kodavade and Madhuri Ganapathi'''
  
−
'''Author: '''Madhuri Ganapathi
+
'''Keywords: Phet simulation, Geometric Optics, lenses, mirrors, rays, optical axis, focal length, object, image, real, virtual, '''radius of curvature, refractive index, diameter, video tutorial.
  
  
−
'''Keywords''': Orca, Windows 10 OS, zip files, Orca Forum, register, login, run input file, video tutorial.
+
{|border=1
−
 
+
−
 
+
−
{| border=1
+
 
|-
 
|-
−
|| '''Visual Cue '''
+
|| '''Visual Cue'''
 
|| '''Narration'''
 
|| '''Narration'''
 
|-
 
|-
−
 
 
|| '''Slide Number 1'''
 
|| '''Slide Number 1'''
  
−
'''Title slide'''
+
'''Title Slide'''
−
|| Welcome to this Spoken Tutorial on '''Installation of ORCA on Windows'''.
+
|| Welcome to this Spoken Tutorial on '''Geometric Optics'''.
−
 
+
 
|-
 
|-
 
|| '''Slide Number 2'''
 
|| '''Slide Number 2'''
  
 
'''Learning Objectives'''
 
'''Learning Objectives'''
 +
|| In this tutorial, we will learn about:
  
−
|| In this tutorial, we will learn to,
+
Image formed by a lens and a mirror.
−
 
+
−
* Download '''orca 5.0.4 '''compressed zip files for Windows OS
+
−
 
+
−
* Extract the compressed files.
+
−
 
+
−
* Run an '''orca''' input file to check the installation.
+
  
 +
Distance between the lens or mirror and the image.
  
 +
Size and nature of the image formed.
 
|-
 
|-
 
|| '''Slide Number 3'''
 
|| '''Slide Number 3'''
Line 39: Line 32:
 
|| This tutorial is recorded using,
 
|| This tutorial is recorded using,
  
−
'''Windows 10 OS'''
+
Ubuntu Linux OS version 22.04
  
−
'''Orca '''version 5.0.4
+
Firefox Web Browser version 126.0.1
−
 
+
−
'''Notepad '''version''' 20H2'''
+
−
 
+
−
'''Firefox Web browser''' version 112.0.2
+
−
 
+
−
 
+
−
Before you begin, please make sure that you are connected to the internet.
+
 
|-
 
|-
 
|| '''Slide Number 4'''
 
|| '''Slide Number 4'''
Line 54: Line 40:
 
'''Pre-requisites'''
 
'''Pre-requisites'''
  
−
|| To follow this tutorial,
+
[https://spoken-tutorial.org/ https://spoken-tutorial.org]
−
* Learner must be familiar with basic computer and Internet skills.
+
 
 +
|| To follow this tutorial the learner should be familiar with topics in basic physics.
  
 +
Please use the link below to access the tutorials on PhET Simulations.
 
|-
 
|-
 
|| '''Slide Number 5'''
 
|| '''Slide Number 5'''
  
−
'''Code Files'''
+
Link for Phet Simulations https://phet.colorado.edu/en/simulations/geometric-optics
  
 +
|| Please use the given link to download the PhET simulation.
 +
|-
 
||  
 
||  
−
* The input file to check the installation is provided in the '''code files''' link.
+
|| Let us begin.
 +
|-
 +
|| '''Slide Number 6'''
  
−
* Please download and extract the file.
+
'''Geometric Optics'''
−
 
+
|| '''Geometric Optics ''' is a branch of optics.  
−
* Make a copy and then use it for practising.
+
  
 +
It shows propagation of light in the form of rays, which pass through a medium.
 
|-
 
|-
−
|| Open a web browser and type '''orca forum ''' in the ''' Google search the web'''.
+
|| '''Slide Number 7'''
  
−
<u>https://orcaforum.kofo.mpg.de/app.php/portal</u>
+
'''PhET Simulations'''
  
 +
|| In this tutorial, we will use '''Geometric Optics PhET Simulation'''.
 +
|-
 +
|| Show the '''Downloads''' folder.
 +
|| I have already downloaded '''Geometric Optics simulation ''' to my '''Downloads''' folder.
 +
|-
 +
|| Double on '''geometric-optics_en.html ''' file.
 +
|| Let us open the simulation.
 +
|-
 +
|| '''Cursor''' on the '''interface'''.
  
−
Point to the '''ORCA Forum''' page.
+
Point to the screens.
−
|| Open your web browser and type '''orca Forum''' and press '''Enter'''.
+
  
−
You can see the first instance as '''ORCA Forum - Portal'''.
+
Point to the Lens screen.
 +
|| This is the interface of '''Geometric Optics simulation'''.
  
−
Click on the link.  
+
It has '''Lens''' and '''Mirror''' screens.
  
−
'''ORCA Forum''' page opens.  
+
Let us explore the '''Lens ''' screen.
 
|-
 
|-
−
|| Point to '''Register''' and '''Login''' links on the top right.
+
|| Point to the lens.
−
|| On the top right side of the page, we have links for '''Register''' and '''Login'''.
+
|| This screen has a spherical convex lens, an object and its image.
 
|-
 
|-
−
|| Cursor on the page.  
+
|| Point to the distance.
 +
|| The distance from the object to the lens is the object distance.  
  
−
Point to the Register link.
+
The distance from the lens to the image is the image distance.  
−
|| If you are a first time user, you have to register on the '''ORCA Forum'''.
+
 
|-
 
|-
−
|| Click on the '''Register '''link.
+
|| Point to the bottom of the interface.
  
−
Point to '''ORCA Forum Registration page.'''
+
Point to the Parameters.
  
−
Scroll down the page.
+
Check the '''Labels''' checkbox.
−
|| Click the '''Register '''link.
+
|| At the bottom we have a box with various optic parameters.
  
−
'''ORCA Forum Registration''' page opens.
+
Let us check the '''Labels''' check box to see the labels of all the items.
−
 
+
−
Scroll down the page.
+
−
 
+
−
 
+
−
Please read the information on the page before clicking the button.  
+
 
|-
 
|-
−
|| Click on '''I agree to these terms''' button.
+
|| Point to the axis
 +
|| The purple dashed line is '''Optical Axis'''.
  
−
Point to '''ORCA Forum – Registration''' page.
+
It is an imaginary line perpendicular to the face of the lens.
−
|| Click on '''I agree to these terms''' button.
+
|-
−
 
+
|| Point to the pencil.
−
The '''Registration''' page refreshes with the details.
+
|| A pencil is used as the default object in this simulation.  
 
|-
 
|-
−
|| Point to the registration details part.
+
|| Point to the object drop down list on the top left.
  
 +
Click the drop down to show the objects.
 +
|| On the top left side, an object drop down list is provided.
  
−
Point to the Email Address text box.
+
Let us click on it to see the objects.  
−
 
+
−
Point to the message.
+
−
|| Here you have to type your details to register on the '''ORCA Forum'''.
+
−
 
+
−
 
+
−
Please enter your valid email address in the '''Email Address '''text box.
+
  
 +
Users can choose different objects and explore.
 
|-
 
|-
−
|| Click on the '''Submit ''' button.
+
|| Point to the pencil.
−
|| Click the '''Submit button ''' to complete the registration.
+
|| I will retain, pencil as the object.  
 
|-
 
|-
−
||  
+
|| Point to the Rays option at the bottom of the screen.  
−
|| The '''orca''' team will send an activation link to the given email address.
+
  
−
You need to click the link sent in the email to get the registration activated.
+
Marginal option chosen by default.
−
|-
+
−
|| Point to login.
+
−
|| I have already registered on the''' ORCA Forum''' so I will login now.
+
−
|-
+
−
|| Fill in the details to login.
+
  
 +
Click on all the radio buttons.
 +
|| Intensity of light can be changed using the '''Rays ''' option at the bottom.
  
−
Click on the '''Login''' button.
+
'''Marginal''' option is chosen by default.
−
|| I will log in using my '''Username''' and '''password'''.  
+
  
 +
We have '''Principal''', '''Many''' and '''None''' as the options.
 +
 +
I will select the''' Marginal''' option.
 
|-
 
|-
−
|| Point to the page.
+
|| Point to the rays.
  
−
Click on the Downloads link on the top left side.
+
Point to focus
−
|| A new page opens.
+
  
 +
Point to the focal length.
  
−
On the top left side, click the '''Downloads''' link.
+
Point to the curvature of the lens.
−
|-
+
−
|| Point to '''Downloads – Categories''' page.
+
  
 +
Point to the focal length.
 +
|| As the rays pass through the lens, they bend slightly towards the axis.
  
−
Point to the various versions on the page.
+
This is due to refraction of the lens.  
  
−
|| The''' Downloads – Categories '''page opens.
+
For more information please refer to the '''Additional Reading material'''.
  
 +
Due to the curvature of the lens, rays from infinity bend and converge to a point.
  
−
The page shows various versions of '''ORCA'''.
+
This point is known as focus.
 +
 
 +
The distance from centre of lens to the focus is the focal length.
 
|-
 
|-
−
|| Click on the '''5.0.4 folder''' link.
+
|| Point to the top and bottom rays.
  
−
Cursor on the page.
+
Point to the centre ray.
−
|| Click on the '''ORCA''' '''5.0.4 folder''' link.
+
|| The rays at the top and bottom bend at larger angles than the one at the centre.  
 +
|-
 +
|| Point to the converged point.
 +
|| This is an example of a converging lens.
  
−
A new page '''ORCA 5.0.4''' opens.
+
It produces real images beyond the focus.
−
 
+
−
A new version of orca might be available at the time of your download.
+
−
|-
+
−
|| Scroll down the page.
+
−
|| Scroll down the page.
+
 
|-
 
|-
−
|| Point to the 3 files.
+
|| Point to the top ray.
−
|| On the page, the required files for ''' Windows OS ''' are provided as 3 zip files.
+
  
−
We need to download all 3 parts one at a time.
+
Point to the bottom ray.
 +
|| A real inverted image is formed when light rays are directed to a fixed point.  
 
|-
 
|-
−
|| Click on [https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 ORCA 5.0.][https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 4][https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 , Windows,64bit, .zip Archive, Part 1/3]
+
|| Point to the focal lengths.
  
 +
Drag the scale and measure the focal length,
 +
|| This lens has same focal length on both the sides.
  
−
Point to the Details
+
Let us measure the distance using the scale.
 +
|-
 +
|| Measure the focal length - 80 cm.
  
−
Point to the file size.
+
Measure the distance from the centre of the lens to the image - 160 cm.
−
|| Click on '''ORCA 5.0.4, part 1 zip file'''.  
+
|| The distance between the focus and the lens is 80 cm.
  
−
The page refreshes.  
+
The distance from the centre of the lens to the image is 160 cm.  
  
−
Here are the details of this file.  
+
A real, inverted image, which is same size as the object, is formed at 2F1.
  
−
The file size is also seen here.
+
Let us put the scale back to its place.
 
|-
 
|-
−
 
+
|| Drag the Radius of curvature slider to minimum.
−
|| Point to the green Download button.
+
|| Let’s drag the '''Radius of Curvature''' slider towards minimum.
−
 
+
−
Click on the Download button.
+
−
|| Click the large green '''Download ''' button at the bottom-right to start downloading.
+
 
|-
 
|-
−
|| Point to the dialog box.
+
|| Point to the radius of curvature and the focal length.
  
 +
Point to the image.
  
−
Click the '''Save button''' to download the file.
+
Drag the Radius of curvature slider to maximum.
−
|| A dialog box opens, which prompts you to save the file.  
+
  
 +
Point to the image.
 +
|| As the radius of curvature decreases, the focal length decreases.
  
−
Click on the''' Save button ''' to download the file.  
+
Observe the size of the image.
  
 +
It becomes smaller.
  
−
In some systems, downloading may start directly without asking to save.
+
As the radius of curvature increases, image moves away from the lens.
  
−
The file takes some time to download due to its large file size.
+
Observe that the image is magnified and blurred.
 
|-
 
|-
−
|| Point to the downloading process.
+
|| Drag the diameter slider.  
−
|| The file downloads to the '''Downloads''' folder for me.
+
  
−
The file may download to the folder as per your system settings.
+
(Drag the slider to right and bring it back to 80)
−
|-
+
|| Let’s drag the diameter slider to see the effects.  
−
|| Point to the downloaded file.
+
−
|| Here is my downloaded file.
+
−
|-
+
−
|| Cursor on the ORCA Forum Downloads page.
+
−
|| Go back to the previous page, where all the files are listed.
+
  
 +
As the diameter increases the image becomes brighter.
 
|-
 
|-
−
|| Show the downloading files.
+
|| Point to the Index of Refraction check box.
  
−
Click on [https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 ORCA 5.0.][https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 4][https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 , Windows, 64bit, .zip Archive, Part 2/3]
+
Drag the slider of the Index of Refraction.
−
 
+
|| Drag the '''Index of Refraction''' slider.
−
|| Now click the link for part 2 '''zip''' file and download it.
+
  
 +
Observe how change in refractive index, bends light to different angles.
 
|-
 
|-
−
|| Click on [https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 ORCA 5.0.][https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 4][https://orcaforum.kofo.mpg.de/app.php/dlext/?view=detail&df_id=172 , Windows, 64bit, .zip Archive, Part 3/3]
+
|| Click on the reset button.
 +
|| Click on the '''Reset''' button to reset the simulation.  
  
−
|| Similarly click the link for part 3 ''' zip''' file and download it.
+
Check the labels check box.
 
|-
 
|-
−
|| In the left panel select '''Downloads'''.
+
|| '''Slide Number 8:'''
−
|| Open the file manager and go to the '''Downloads '''directory.
+
  
−
Notice the three downloaded '''zip''' files.
+
'''Table 1'''
−
|-
+
−
|| Enlarge the folder '''orca ''' using '''Ctrl ++'''.
+
  
  
−
Right-click in the '''Downloads''' folder.
+
<u>'''Table 1: Image formation by a convex lens'''</u>
  
 +
{|border=1
 +
|-
 +
|| Object Position
 +
|| Image Position
 +
|| Image Size
 +
|| Nature
 +
|-
 +
|| At 2F1
 +
|| At 2F2
 +
|| Same size as object
 +
|| Real,inverted
 +
|-
 +
|| Beyond 2F1
 +
|| Between F2 and 2F2
 +
|| Diminished
 +
|| Real,inverted
 +
|-
 +
|| Between F1 and 2F1
 +
|| Beyond 2F2
 +
|| Magnified
 +
|| Real,inverted
 +
|-
 +
|| At F1
 +
|| Infinity
 +
|| Highly magnified
 +
|| Real,inverted
 +
|-
 +
|| Between F1 and O
 +
|| On the same side as object
 +
|| Magnified
 +
|| Virtual, erect
 +
|-
 +
|| Infinity
 +
|| F2
 +
|| Point Sized
 +
|| Real,inverted
 +
|-
 +
|}
  
−
From the context menu select the '''New Folder''' option.
+
Concave lens forms virtual and erect image on the same side of the lens between F1 and O.  
−
|| Let us create a new directory and move the''' zip ''' files to this directory.
+
  
 +
It is always diminished.
  
−
To create a new directory, right-click in the '''Downloads''' directory.
+
|| This table shows the Image formation by a convex lens.
 +
|-
 +
|| Show the table here and point to different cases.
  
 +
Point to case 1 in the table.
 +
|| Here are 6 instances of placing an object.
  
−
From the context menu select the '''New Folder''' option.
+
We have already discussed case 1.  
 
|-
 
|-
−
|| Type the name as '''orca '''in the '''Folder Name''' text box.
+
|| Case 2: Beyond 2F.
−
|| Name the folder as '''orca'''.
+
  
−
|-
+
Point to case 2 in the table.
−
|| Point to the '''orca''' directory.
+
  
−
Press and hold the '''Ctrl''' key,
+
Switch to the simulation.
  
−
Click on all 3 files to select them.
+
Drag the lens beyond 2F.
−
|| Let’s move the 3 downloaded zip files to this newly created '''orca''' directory.
+
  
 +
(drag the object - so that distance between lens and image is around 180 cm)
 +
|| Case 2: Let us discuss the case of placing the object beyond 2F1.
  
−
Press and hold the '''Ctrl''' key and click the 3 files to select them.
+
Let’s measure the distance between the object and lens.  
−
|-
+
−
|| Drag and drop into '''orca''' folder.
+
−
|| Drag and drop them into the '''orca''' directory.
+
  
−
|-
+
It is 160 cm.
−
|| Point to the zip files.
+
−
|| Now we will extract the files one by one.
+
  
−
|-
+
Let us move the object beyond this measured distance that is beyond 2F1.
−
|| Right-click on '''orca part1 zip '''file.
+
  
−
From the context menu select '''Extract All''' option.
+
The object distance is 180 cm.
−
|| Right-click on '''orca''' part1''' zip '''file.
+
  
−
From the context menu select '''Extract All''' option.
+
Let us measure the distance between the lens and the image.  
  
−
|-
 
−
|| Point to the dialog box.
 
  
 +
It is 150 cm.
  
−
Click the '''Extract '''button.
+
This distance is less than 2F but more than F.
−
|| '''Extract Compressed Folders '''dialog box opens.
+
  
−
In the box click on the '''Extract''' button at the bottom-right.
+
Hence we can say that the image is formed between F and 2F.
  
−
|-
+
A real, inverted and diminished image is formed.
−
|| Point to the progress bar.
+
−
|| Extraction progress is shown.
+
  
−
Wait for the extraction to complete.
+
Let us put the scale back to its place.
 
|-
 
|-
−
|| Point to '''orca_5_0_4_win64_msmpi10_part1'''
+
|| '''Slide Number 9'''
  
−
folder.
+
'''Assignment'''
  
−
|| A folder with the same name as the '''zip '''file is created.
+
Show table on the slide.
 +
|| As an assignment,
  
−
All the files get extracted to this folder.
+
Place the object in other positions and
−
|-
+
−
|| Point to '''orca_5_0_4_win64_msmpi10_part2''' folder.
+
−
|| In the same manner extract the '''orca''' part2 '''zip '''file.
+
  
−
Again a folder with the same name as the '''zip '''file is created.
+
Check the image formed by the convex lens.
  
 +
Use the table for your reference.
  
−
All the files are extracted into it.
+
Follow the steps as shown in case 2.
−
 
+
 
|-
 
|-
−
|| Point to orca_5_0_4_win64_msmpi10_part3
+
|| Click on concave lens option
−
 
+
|| Let us click on the concave lens button at the top.
−
folder.
+
−
|| Similarly extract the part 3 '''zip''' file.
+
−
 
+
 
|-
 
|-
−
|| Point to the directories.
+
|| Point to the concave lens.
 +
|| A concave lens is a diverging lens.
  
−
Double click to open them.
+
It generates a virtual and erect image.
−
|| We have completed the extraction of all the parts.
+
  
−
 
+
The point where the rays seem to diverge is extended backwards.
−
We now have three directories with the extracted files.
+
 
|-
 
|-
−
|| point to '''orca''' directory.
+
|| Point to the rays.
−
|| We have to place all the extracted files in the '''orca''' directory.
+
|| As the rays pass through the lens, they bend slightly outwards from the axis.  
  
 +
This is due to refraction of the lens. So the rays diverge.
 
|-
 
|-
−
|| Ctrl + A to Select.
+
|| Point to the focus.
  
−
Ctrl + X to Cut.
+
(Drag as far as possible but let it be in the screen)
 +
|| The focus is at the same side of the object.  
  
−
Ctrl + V to Paste.
+
Let us place the object beyond F1.  
−
|| Open the directories one by one.
+
−
 
+
−
 
+
−
Select all the files in each of them.
+
−
 
+
−
Cut and paste them into the '''orca''' directory.
+
  
 +
A diminished, virtual and erect image is formed between focus and lens.
 
|-
 
|-
−
|| Select and press Delete key on the keyword.
+
|| Drag the object close to the lens.
−
|| You may delete the empty directories.  
+
|| Now let us drag the object close to the concave lens.
  
 +
Observe that the size of the image increases.
 
|-
 
|-
−
|| Select and press Delete key on the keyboard.
+
|| Click on the Mirror.
−
|| You may also delete the 3 zip files to save the disk space.
+
|| Now let us explore the ''' Mirror''' screen.
 +
|-
 +
|| Point to the 3 types of mirror.
 +
|| This screen has 3 types of mirrors.  
  
 +
By default a concave mirror is selected.
 
|-
 
|-
−
|| Point to the compiled files in the folder.
+
|| Click on the labels check box.
 +
|| Click on the labels checkbox to see the labels of all the items.
 +
|-
 +
|| Point to the front side.
  
−
Point to the '''orca''' file.
+
Point to the back side.
−
|| All the files must be placed together for the orca program to function.
+
|| For the concave mirror, front or left side is the reflecting surface.  
  
−
Here, all the files are already compiled and are in executable format.
+
Hence, the object is placed on this side.  
  
−
All calculations will run using the '''orca '''executable file.
+
Right side is the non-reflecting surface.
 
|-
 
|-
−
|| Point to the '''carbonmonoxide '''folder in the Downloads folder.
+
|| Point to the distance.
−
|| Now we will run an input file to check the installation of '''orca'''.
+
|| The distance between the object and mirror is always positive.  
 +
|-
 +
|| Point to the image on the front side.
  
−
This file is provided to you in the '''Code Files''' link.
+
Drag the object and point to the image on the back side.
  
−
Please download and extract it to a path convenient to you.
+
Point to the image formed.
 +
|| If the image is on the front side, the distance is positive.  
  
−
I have downloaded the file to my '''Downloads '''directory.
+
This is a real and inverted image.
  
 +
Let us drag the object close to the mirror and see the image.
 +
 +
A virtual and enlarged image is formed on the right side of the object.
 
|-
 
|-
−
|| Point to the Search bar.
+
|| '''Slide Number 10:'''
 +
 
 +
Image formation by a Concave mirror.
  
−
Type''' command prompt'''.
 
−
|| Let us open the command prompt.
 
  
−
In the '''Search bar''' next to the '''Start''' icon type '''command prompt'''.
+
<u>'''Table 2 : Image formation by a concave mirror'''</u>
  
 +
{|border=1
 +
|-
 +
|| Object Position
 +
|| Image Position
 +
|| Image Size
 +
|| Nature
 +
|-
 +
|| At 2F1
 +
|| At 2F2
 +
|| Same size as object
 +
|| Real,inverted
 +
|-
 +
|| Between F1 and O
 +
|| Behind the mirror
 +
|| Magnified
 +
|| Virtual, erect
 +
|-
 +
|| Beyond 2F1
 +
|| Between F2 and 2F2
 +
|| Diminished
 +
|| Real,inverted
 +
|-
 +
|| Between F1 and 2F1
 +
|| Beyond 2F2
 +
|| Magnified
 +
|| Real,inverted
 +
|-
 +
|| At F1
 +
|| Infinity
 +
|| Highly magnified
 +
|| Real,inverted
 +
|-
 +
|| Infinity
 +
|| At the focus F2
 +
|| Point Sized
 +
|| Real,inverted
 
|-
 
|-
−
|| Click on it to select command prompt
+
|}
−
|| Select '''Command Prompt''' from the shown list.
+
  
−
'''Command Prompt''' opens.
+
|| This is the table for the Image formation by a concave mirror.
 
|-
 
|-
−
|| At the prompt:
+
|| Only Narration.
  
−
type '''cd Downloads >> '''press Enter.
+
Case 1:
−
|| At the prompt type '''cd space Downloads '''and press '''Enter.'''
+
|| Now, let us discuss an instance of placing an object at 2F1.  
  
−
Our ''' orca''' directory is in the '''Downloads''' directory.
+
Let us reset the simulation.  
  
 +
And check the labels check box.
 
|-
 
|-
−
|| Type '''orca\orca '''press Enter.
+
|| Drag the scale.
−
|| Then type '''orca\orca '''and press '''Enter'''.
+
|| Drag the scale to measure the distance.  
  
−
|-
+
The distance between the focal point and the mirror is 90 cm.  
−
|| Point to the message.
+
−
|| A message appears.
+
  
−
'''This program requires the name of a parameter file as argument'''
+
Let us measure the distance from the centre of the mirror to 2F1.
  
−
'''For example ORCA TEST.INP'''
+
It is 180 cm.
  
−
|-
+
Let us place the object at this point.
−
||'''orca\orca carbonmonoxide\carbonmonoxide.inp'''
+
−
|| The input file is saved in my Downloads directory.
+
  
−
Now type '''orca\orca''' space '''carbonmonoxide\carbonmonoxide.inp '''and press '''Enter.'''
+
A real inverted image, same size as the object, is formed below the object.
  
−
 
+
Let us put the scale back to its place.
−
Users have to type the commands as per their folder structure.
+
 
|-
 
|-
−
|| Show the processing.
+
|| '''Slide Number 11'''
  
−
Point to the final output.
+
'''Assignment'''
−
|| Observe that, the input file is processed in the orca environment.
+
  
−
The output is generated with ORCA terminated normally.
+
Show table on the slide.
 +
|| As an assignment,
  
−
|-
+
Place the object in other positions and
−
|| Open and show the output files in the directory.
+
−
|| The generated output files are saved in the same directory as the input file.
+
  
 +
check the image formed by the concave mirror.
  
−
This confirms the successful installation of '''orca'''.
+
Use the table for your reference.
−
|-
+
−
|| Only Narration.
+
−
|| With this, we come to the end of this tutorial.
+
  
−
Let us summarise.
+
Follow the steps as shown in case 1.
 
|-
 
|-
−
|| '''Slide Number 7'''
+
|| Click on the convex mirror button.
−
 
+
−
'''Summary '''
+
  
−
|| In this tutorial, we have learnt to,
+
Drag the object back and forth and show a virtual image.
 +
|| Now let us click the convex mirror button.
  
−
* Download orca 5.0.4 compressed zip files for Windows OS
+
For this mirror left side is the front side.  
  
−
* Extract the compressed files.
+
The object is placed on this side.  
  
−
* Run an o'''rca''' input file to check the installation
+
The right side is the back side.
  
 +
A convex mirror always forms a virtual image.
 
|-
 
|-
−
|| '''Slide Number 8'''
+
|| Drag the object back and forth to see the image.
  
−
'''Assignment'''
+
Point to the image.
 +
|| Let’s drag the object back and forth to see where the image is formed.
  
−
'''https://sites.google.com/site/orcainputlibrary/home'''
+
It is formed on the back side of the mirror.
  
−
|| As an assignment, users can
+
Observe that the image formed is always a virtual image
 +
|-
 +
|| Drag the object and show the size of the image.
 +
|| The image formed is always smaller in size than the object.
 +
|-
 +
|| Only Narration
 +
|| With this we come to the end of this tutorial.
  
−
Go through '''ORCA Input Library''' and check the updates for '''input files'''.
+
Let us summarise.
 +
|-
 +
|| '''Slide Number 12'''
  
−
Check the '''ORCA Forum''' for queries.
+
'''Summary'''
 +
|| In this tutorial, we have learnt about,
 +
* Image formed by a lens and a mirror.
 +
* The distance between the lens or mirror and the image
 +
* Size and nature of the image.
 +
|-
 +
|| '''Slide Number 13'''
  
 +
'''Assignment'''
 +
|| As an assignment,
 +
 +
Explore the Flat mirror option on your own.
 
|-
 
|-
−
|| '''Slide Number 9'''
+
|| '''Slide Number 14'''
  
−
'''Spoken Tutorial Project'''
+
'''About the Spoken Tutorial Project'''
−
 
+
|| The video at the following link summarises the Spoken Tutorial project.
−
|| The video at the following link summarises the Spoken Tutorial Project.
+
  
 
Please download and watch it.
 
Please download and watch it.
−
 
 
|-
 
|-
−
|| '''Slide Number 10'''
+
|| '''Slide Number 15'''
  
 
'''Spoken Tutorial workshops'''
 
'''Spoken Tutorial workshops'''
−
|| We conduct workshops using spoken tutorials and give certificates.
+
|| The '''Spoken Tutorial Project '''team:
  
 +
conducts workshops and gives certificates
  
 
For more details, please write to us.
 
For more details, please write to us.
 
|-
 
|-
−
|| '''Slide Number 11'''
+
|| '''Slide Number 16'''
−
 
+
−
'''Forum for questions'''
+
−
 
+
−
||
+
−
* Do you have questions in THIS '''Spoken Tutorial'''?
+
−
* Please visit this site.
+
−
* Choose the minute and second where you have the question.
+
−
* Explain your question briefly.
+
−
* The spoken tutorial project will ensure an answer.
+
  
−
You will have to register on this website to ask questions.
+
'''Forum for specific questions:'''
 +
|| Please post your timed queries in this forum.
 
|-
 
|-
−
|| '''Slide Number 13'''
+
|| '''Slide Number 17'''
  
 
'''Acknowledgement'''
 
'''Acknowledgement'''
−
 
+
|| The Spoken Tutorial project was established by the Ministry of Education, Govt. of India.
−
|| The '''Spoken Tutorial''' project was established by the Ministry of Education (MoE), Govt. Of India
+
 
|-
 
|-
−
||Only Narration.
+
|| Thank you
−
|| This is Madhuri Ganapathi from IIT, Bombay signing off.
+
|| This tutorial is contributed by FOSSEE and Spoken Tutorial Project, IIT Bombay.
−
 
+
  
 +
Thank you for joining.
 
|-
 
|-
 
|}
 
|}

Latest revision as of 15:29, 29 January 2025

Title of the script: Geometric Optics

Author: Shraddha Kodavade and Madhuri Ganapathi

Keywords: Phet simulation, Geometric Optics, lenses, mirrors, rays, optical axis, focal length, object, image, real, virtual, radius of curvature, refractive index, diameter, video tutorial.


Visual Cue Narration
Slide Number 1

Title Slide

Welcome to this Spoken Tutorial on Geometric Optics.
Slide Number 2

Learning Objectives

In this tutorial, we will learn about:

Image formed by a lens and a mirror.

Distance between the lens or mirror and the image.

Size and nature of the image formed.

Slide Number 3

System Requirements

This tutorial is recorded using,

Ubuntu Linux OS version 22.04

Firefox Web Browser version 126.0.1

Slide Number 4

Pre-requisites

https://spoken-tutorial.org

To follow this tutorial the learner should be familiar with topics in basic physics.

Please use the link below to access the tutorials on PhET Simulations.

Slide Number 5

Link for Phet Simulations https://phet.colorado.edu/en/simulations/geometric-optics

Please use the given link to download the PhET simulation.
Let us begin.
Slide Number 6

Geometric Optics

Geometric Optics is a branch of optics.

It shows propagation of light in the form of rays, which pass through a medium.

Slide Number 7

PhET Simulations

In this tutorial, we will use Geometric Optics PhET Simulation.
Show the Downloads folder. I have already downloaded Geometric Optics simulation to my Downloads folder.
Double on geometric-optics_en.html file. Let us open the simulation.
Cursor on the interface.

Point to the screens.

Point to the Lens screen.

This is the interface of Geometric Optics simulation.

It has Lens and Mirror screens.

Let us explore the Lens screen.

Point to the lens. This screen has a spherical convex lens, an object and its image.
Point to the distance. The distance from the object to the lens is the object distance.

The distance from the lens to the image is the image distance.

Point to the bottom of the interface.

Point to the Parameters.

Check the Labels checkbox.

At the bottom we have a box with various optic parameters.

Let us check the Labels check box to see the labels of all the items.

Point to the axis The purple dashed line is Optical Axis.

It is an imaginary line perpendicular to the face of the lens.

Point to the pencil. A pencil is used as the default object in this simulation.
Point to the object drop down list on the top left.

Click the drop down to show the objects.

On the top left side, an object drop down list is provided.

Let us click on it to see the objects.

Users can choose different objects and explore.

Point to the pencil. I will retain, pencil as the object.
Point to the Rays option at the bottom of the screen.

Marginal option chosen by default.

Click on all the radio buttons.

Intensity of light can be changed using the Rays option at the bottom.

Marginal option is chosen by default.

We have Principal, Many and None as the options.

I will select the Marginal option.

Point to the rays.

Point to focus

Point to the focal length.

Point to the curvature of the lens.

Point to the focal length.

As the rays pass through the lens, they bend slightly towards the axis.

This is due to refraction of the lens.

For more information please refer to the Additional Reading material.

Due to the curvature of the lens, rays from infinity bend and converge to a point.

This point is known as focus.

The distance from centre of lens to the focus is the focal length.

Point to the top and bottom rays.

Point to the centre ray.

The rays at the top and bottom bend at larger angles than the one at the centre.
Point to the converged point. This is an example of a converging lens.

It produces real images beyond the focus.

Point to the top ray.

Point to the bottom ray.

A real inverted image is formed when light rays are directed to a fixed point.
Point to the focal lengths.

Drag the scale and measure the focal length,

This lens has same focal length on both the sides.

Let us measure the distance using the scale.

Measure the focal length - 80 cm.

Measure the distance from the centre of the lens to the image - 160 cm.

The distance between the focus and the lens is 80 cm.

The distance from the centre of the lens to the image is 160 cm.

A real, inverted image, which is same size as the object, is formed at 2F1.

Let us put the scale back to its place.

Drag the Radius of curvature slider to minimum. Let’s drag the Radius of Curvature slider towards minimum.
Point to the radius of curvature and the focal length.

Point to the image.

Drag the Radius of curvature slider to maximum.

Point to the image.

As the radius of curvature decreases, the focal length decreases.

Observe the size of the image.

It becomes smaller.

As the radius of curvature increases, image moves away from the lens.

Observe that the image is magnified and blurred.

Drag the diameter slider.

(Drag the slider to right and bring it back to 80)

Let’s drag the diameter slider to see the effects.

As the diameter increases the image becomes brighter.

Point to the Index of Refraction check box.

Drag the slider of the Index of Refraction.

Drag the Index of Refraction slider.

Observe how change in refractive index, bends light to different angles.

Click on the reset button. Click on the Reset button to reset the simulation.

Check the labels check box.

Slide Number 8:

Table 1


Table 1: Image formation by a convex lens

Object Position Image Position Image Size Nature
At 2F1 At 2F2 Same size as object Real,inverted
Beyond 2F1 Between F2 and 2F2 Diminished Real,inverted
Between F1 and 2F1 Beyond 2F2 Magnified Real,inverted
At F1 Infinity Highly magnified Real,inverted
Between F1 and O On the same side as object Magnified Virtual, erect
Infinity F2 Point Sized Real,inverted

Concave lens forms virtual and erect image on the same side of the lens between F1 and O.

It is always diminished.

This table shows the Image formation by a convex lens.
Show the table here and point to different cases.

Point to case 1 in the table.

Here are 6 instances of placing an object.

We have already discussed case 1.

Case 2: Beyond 2F.

Point to case 2 in the table.

Switch to the simulation.

Drag the lens beyond 2F.

(drag the object - so that distance between lens and image is around 180 cm)

Case 2: Let us discuss the case of placing the object beyond 2F1.

Let’s measure the distance between the object and lens.

It is 160 cm.

Let us move the object beyond this measured distance that is beyond 2F1.

The object distance is 180 cm.

Let us measure the distance between the lens and the image.


It is 150 cm.

This distance is less than 2F but more than F.

Hence we can say that the image is formed between F and 2F.

A real, inverted and diminished image is formed.

Let us put the scale back to its place.

Slide Number 9

Assignment

Show table on the slide.

As an assignment,

Place the object in other positions and

Check the image formed by the convex lens.

Use the table for your reference.

Follow the steps as shown in case 2.

Click on concave lens option Let us click on the concave lens button at the top.
Point to the concave lens. A concave lens is a diverging lens.

It generates a virtual and erect image.

The point where the rays seem to diverge is extended backwards.

Point to the rays. As the rays pass through the lens, they bend slightly outwards from the axis.

This is due to refraction of the lens. So the rays diverge.

Point to the focus.

(Drag as far as possible but let it be in the screen)

The focus is at the same side of the object.

Let us place the object beyond F1.

A diminished, virtual and erect image is formed between focus and lens.

Drag the object close to the lens. Now let us drag the object close to the concave lens.

Observe that the size of the image increases.

Click on the Mirror. Now let us explore the Mirror screen.
Point to the 3 types of mirror. This screen has 3 types of mirrors.

By default a concave mirror is selected.

Click on the labels check box. Click on the labels checkbox to see the labels of all the items.
Point to the front side.

Point to the back side.

For the concave mirror, front or left side is the reflecting surface.

Hence, the object is placed on this side.

Right side is the non-reflecting surface.

Point to the distance. The distance between the object and mirror is always positive.
Point to the image on the front side.

Drag the object and point to the image on the back side.

Point to the image formed.

If the image is on the front side, the distance is positive.

This is a real and inverted image.

Let us drag the object close to the mirror and see the image.

A virtual and enlarged image is formed on the right side of the object.

Slide Number 10:

Image formation by a Concave mirror.


Table 2 : Image formation by a concave mirror

Object Position Image Position Image Size Nature
At 2F1 At 2F2 Same size as object Real,inverted
Between F1 and O Behind the mirror Magnified Virtual, erect
Beyond 2F1 Between F2 and 2F2 Diminished Real,inverted
Between F1 and 2F1 Beyond 2F2 Magnified Real,inverted
At F1 Infinity Highly magnified Real,inverted
Infinity At the focus F2 Point Sized Real,inverted
This is the table for the Image formation by a concave mirror.
Only Narration.

Case 1:

Now, let us discuss an instance of placing an object at 2F1.

Let us reset the simulation.

And check the labels check box.

Drag the scale. Drag the scale to measure the distance.

The distance between the focal point and the mirror is 90 cm.

Let us measure the distance from the centre of the mirror to 2F1.

It is 180 cm.

Let us place the object at this point.

A real inverted image, same size as the object, is formed below the object.

Let us put the scale back to its place.

Slide Number 11

Assignment

Show table on the slide.

As an assignment,

Place the object in other positions and

check the image formed by the concave mirror.

Use the table for your reference.

Follow the steps as shown in case 1.

Click on the convex mirror button.

Drag the object back and forth and show a virtual image.

Now let us click the convex mirror button.

For this mirror left side is the front side.

The object is placed on this side.

The right side is the back side.

A convex mirror always forms a virtual image.

Drag the object back and forth to see the image.

Point to the image.

Let’s drag the object back and forth to see where the image is formed.

It is formed on the back side of the mirror.

Observe that the image formed is always a virtual image

Drag the object and show the size of the image. The image formed is always smaller in size than the object.
Only Narration With this we come to the end of this tutorial.

Let us summarise.

Slide Number 12

Summary

In this tutorial, we have learnt about,
  • Image formed by a lens and a mirror.
  • The distance between the lens or mirror and the image
  • Size and nature of the image.
Slide Number 13

Assignment

As an assignment,

Explore the Flat mirror option on your own.

Slide Number 14

About the Spoken Tutorial Project

The video at the following link summarises the Spoken Tutorial project.

Please download and watch it.

Slide Number 15

Spoken Tutorial workshops

The Spoken Tutorial Project team:

conducts workshops and gives certificates

For more details, please write to us.

Slide Number 16

Forum for specific questions:

Please post your timed queries in this forum.
Slide Number 17

Acknowledgement

The Spoken Tutorial project was established by the Ministry of Education, Govt. of India.
Thank you This tutorial is contributed by FOSSEE and Spoken Tutorial Project, IIT Bombay.

Thank you for joining.

Contributors and Content Editors

Madhurig

Retrieved from "https://script.spoken-tutorial.org/index.php?title=PhET-Simulations-for-Physics/C2/Geometric-Optics/English&oldid=56814"