Lens

Paper, Order, or Assignment Requirements

please  use this book as a part of the evidence ( Advance Physics For You written by Johnson, K – Hewett,S – Holt, S – Miller, J ) and the file which i will upload.

* Show all the calculation which should be provide

Experiment:  Lens

You are provided with an optical rail, large lamp, stands and a box containing convex lens, photographic slide and plastic ruler.  Be aware that the rail has a distance scale on it and all the rail holders have a line on one side of them only.  You must put the holders on so that the line is on the side where the scale is.

Task 1: To calculate the focal length of the given lens

1. Mount the lens in the lens holder and insert the lens and photographic slide using the holder onto the rails. Lamp is on one end and screen at the other end.
2. Move the lens to a desired position and then move the object until the image forms in the screen. Vary the position of the object until a crisp, focused image is formed. {Note: image is inverted; you may want to place the slide upside down}.
3. Record the distance of object (d0) and distance of image (di) in your tabular column.
4. Repeat step 2 and 3 and record the values of do and di. Take at least 6 readings.
5. Draw a graph for 1/do vs 1/di. The intercepts will give you the value of 1/f.  Calculate f from this.
6. Check the value of f using lens equation,

1/f = 1/d0 + 1/di

Where f is the focal length of the lens

do is thedistance of the object from the lens

di is the distance of the image from the lens

1. To calculate the focal length of the given lens

 d0 (unit) di (unit) f (unit) 8 14 5.09 10 10 5 12 9 5.14 15 7.5 5

Task 2:  Magnification of lens

1. Replace the slide with the plastic ruler shard.
2. Adjust the position of lens and object until a clear image is observed.
3. Record the values of do and di.
4. Use ruler to measure the image of “5mm” of the ruler. Calculate the magnification, M.

M = Image size / Object size

{You will get magnification (M) by dividing your measurement by 5mm.}

1. Repeat the procedure for at least 6 different positions and record the readings.
2. Explain the characteristics of the image (Is the image magnified or diminished? Is it upright?)
3. Draw a graph for M vs di. The gradient of the line will give 1/f.  Calculate f from this.
4. Check the focal length with the focal length from Task 1.

Size of Object 1 cm

To find the magnification of the lens

 d0 (unit) di (unit) Size of the image(unit) Magnification, M 7 18 2.5 2.57 10 10 1 1 15 7.5 0.5 0.5

Structure

1. Aim of the experiment
• Explain the aim of the experiment.
1. Introduction
• Mention the experiment.
• Explain the principle of the experiment.
1. Equipment used
• List the equipment you used.
1. Safety
• Did you consider any safety issues while carrying out the experiment? Explain.
1. . Method
• Provide any ray diagram or diagram that you used.
• Explain the formula and terms used with appropriate units.
• Explain the procedure.
1. Results
• Include the tables.
• Attach the relevant graphs.
• Show the working for each type of calculation.
1. Uncertainties
• Explain the uncertainty involved in the experiment.
• Error analysis should be provided here.( Calculation) (systematic errors)
1. Discussion
• Discuss your result
• Relate your findings to the theory.
• What result did you expect? What did you get? If you got unexpected result what went wrong? How it could have been rectified.
1. Conclusion
• Give your conclusion.
1. Bibliography
• List the references you used (books, websites etc.). Harvard referencing should be used.  Don’t forget the citation.

Note:

• Read your report and use spell check.
• Do not cut and paste from websites.
• Don’t forget to provide reference
• If you don’t get exact answer, just discuss why you didn’t get the answer and how the method can be improved or how the error can be reduced.