SMA AL MADRASAH AL ALAWIYAH

AD DINIAH

CHAPTER :- PHYSICS - LIGHT ( FORM 4 )

TITLE :- LENSES IN THE OPTICAL DEVICES

Name : Munira Binti Mahammad Noor

I/C Number : 940723-14-6178

Teacher’s Name : Sallmah Binti Man

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CONTENT

CONTENT PAGEContentIntroduction

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Simple Microscope 4-5Compound Microscope 6-7Astronomical Telescope 8-9Single Lens Camera 10-11Slide Projector 12-13Conclusion 14References 15

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INTRODUCTIONSince early thousand years, lenses have been used to observe many things and items that

cannot be detected by human eyes as human eyes only have a limited view due to its eye lens. Therefore, many optical devices like simple microscope, compound microscope, astronomical microscope, single-lens camera and slide projector have been constructed to discover the objects from giant-size until micro-size and even in nano-size. Thus, we cannot deny that these optical devices have been helped us in many researches and our own life due to the knowledge of lenses which consist of elaborations regarding the direction of rays and the form of images. Hence, different optical devices perform different ray diagrams, thus different functions.

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SIMPLE MICROSCOPE

Figure 1 : The side-view of the simple microscope Figure 2 : The simple microscope

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Ray diagrams :

- Consists of a single convex lens with short focal length.- A virtual, magnified and upright image is formed.- The shortest distance that the image can be focused on the eye is 25 cm.

Functions :

- To magnify small objects.- To produce larger and sharper images of objects.

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COMPOUND MICROSCOPE

Figure 1 : The side-view of compound microscope Figure 2 : The compound microscope

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Ray diagrams :

- Consist of two convex lens with smaller focal length and smaller aperture near the object- A magnified, inverted, and virtual image is formed.- The angular magnification can be increased by using the objective and eyepiece of smaller focal

lengths.

Functions :

- To view near and very small objects.

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ASTRONOMICAL TELESCOPE

Figure 1 : The side-view of astronomical telescope Figure 2 : The astronomical telescope

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Ray diagrams :

- Consist of two convex lenses which the objective lens has larger focal length and larger aperture while the eyepiece has shorter focal length and shorter aperture.

- A magnified, inverted and virtual image is formed.

Functions :

- To view large distant objects.

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SINGLE-LENS CAMERA

Figure 1 : The side-view of single lens camera Figure 2 : The single lens camera

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Ray diagrams :

- The image formed is adjusted by changing the shape of its lens.- The standard lens for a single lens camera usually has focal length of 40 cm

Functions :

- To get a sharper images from the objects.

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SLIDE PROJECTOR

Figure 1 : The side-view of slide projector Figure 2 : The slide projector

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Ray diagrams :

- A diverged, real and upright image is formed.- The image can be correctly oriented by flipping over and rotating each slide- The real images formed onto a screen are always inverted and reversed left-to-right.

Functions :

- To view photographic slides.

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CONCLUSIONIt’s obviously that different optical devices have different lenses and rays produced, thus

provide different functions which can ease us in our daily life. By using the concept of lenses, more optical devices can be constructed which may able us to view the smallest objects in the future. Therefore, I had learned that lenses are very useful in our life. Without lenses, people with sightness-problem will stay suffer and the scientific researches cannot be explored successively. Thus, I also learned that some knowledge of science can ease and able us to observe, explore and discover new things that cannot be reached by the human’s eye. Last but not least, I’m very proud with the scientists who had explored the world of lenses and constructed many optical devices which contribute many things in our life.

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REFERENCE1. Focus Ace SPM Physics, S.L.Chang, Koay Kheng Chuan, Yew Kok Leh, First published

2009, Penerbitan Pelangi Sdn. Bhd. 2. http://www.joelnicholsblog.wordpress.com3. http://www.sinaphile.wordpress.com4. http://www.freesciencefairproject.com5. http://www.hitechreview.com6. http://www.dansdata.com7. http://www.pentaxforums.com8. http://www.tutorvista.com9. http://www.diytrade.com10. http://www.flickr.com11. http://www.coburgphysics12.edublogs.org12. http:/www.stonecrestgib.wikispaces.com13. http://www.intranet.desaleshighschool.com14. http://www.micro.magnet.fsu.edu15. http://www.digitalsmicroscope.com16. http://www.tutornext.com/simple-microscope-examples/5533 17. http://books.google.com.my/books?

id=BwistUlpZ7cC&pg=PA899&lpg=PA899&dq=the+explanation+of+ray+diagram+in+the+single+lens+camera&source

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18. http://dev.physicslab.org/Document.aspx? doctype=3&filename=GeometricOptics_ConvergingLenses.xml

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