• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Aim: to find the refractive index of water

Extracts from this document...

Introduction

The refractive index of water

Aim: to find the refractive index of water

Data collection

real depth RD/cm

apparent depth AD/cm

RD+-0.05cm

AD+-0.05cm

8.85

6.15

6.30

7.10

6.75

9.30

6.70

7.70

7.65

7.15

9.60

7.95

7.20

6.90

7.05

14.95

11.65

11.90

10.75

12.35

Data processing

For the first trial,

Average apparent depth=(AD1+AD2+ AD3+ AD4)/4

      =(6.15+6.30+7.10+6.75)/4=6.57

Average uncertainty=(ADMAX-ADMIN)/2=(7.10-6.15)

...read more.

Middle

Real depth RD/cm

Average apparent depth AD/cm

RD+-0.05cm

AD+-xcm

8.85

6.57+-0.47

9.30

7.30+-0.50

9.60

7.27+-0.52

14.95

11.66+-0.57

image00.png

best-fit gradient: (14.9-8.8)/(11.7-6.6) =1.20

worst fit line with maximum gradient: (14.95-8.85)/( 11.66-0.57-6.57-0.47)=1.51

worst fit line with minimum gradient: (14.95-8.85)/( 11.66+0.57-6.57+0.47)= 1.00

Average uncertainty=(GMAX-GMIN)/2=(1.51-1.00)/2=0.26

So the refractive index is 1.20+-0.26

Percentage uncertainty=0.26/1.20=21.7%

Percentage discrepancy=(1.33-1.20)/1.33=9.8%

Conclusion

So there is a proportional relationship between apparent depth and the real depth. The gradient shows the experimental value of the refractive index of water is 1.20+-0.26.

The systematic error could be the thickness of the mirror. Then, the position of the virtual image in the water will appear to be higher then the actual one. This will affect the apparent depth and thus the refractive. The other systematic error is the bulge of the middle part of water compared to area all around.

...read more.

Conclusion

2 I should change the cork into a magnet next time so that it can attract the pin without changing the length of it. Then two pins will just be in the same size removing a systematic error.

3 from the graph it’s shown that my three previous values are quite close to each other and the forth one appears to be far away. Next time, I should find more cups with bigger difference in sizes compared to each other. Then, the data range will also increase, improving the accuracy. More trials can also reduce some random errors.

4 in choosing the mirror, I should choose the one as thin as possible. So thin that the thickness of it can be ignorable and this can help me get a bigger control both independent and dependent variable.


Reference

1 http://hypertextbook.com/facts/2005/AmyHo.shtml

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Microscopes & Lenses section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Microscopes & Lenses essays

  1. In this experiment I will be investigating the efficiency of a motor. I hope ...

    It will also be important to make sure that the ruler is straight as well as any other equipment when measuring, and not at an angle. This could cause an error in the distance being measured. To overcome this I may use a setsquare to line up the equipment.

  2. Lenses experiment

    focal length of lens/cm Average object distance/cm Description of image Average diameter of image/cm Average magnification 10.0 10.0 Indescribable Immeasurable / 10.0 12.0 Real, magnified & inverted 8.9 4.45 10.0 14.0 Real, magnified & inverted 4.5 2.25 10.0 16.0 Real, magnified & inverted 3.1 1.55 10.0 18.0 Real, magnified &

  1. My experiments focus is to obtain an accurate measurement for a specific lenss power.

    can obtain an estimation of the -1/F value and hence the power. At the intercept 1/V=0 and so 1/U+1/F=0. Rearranging, we find that 1/U= -1/F and so I just need to covert the 1/U value to positive to find the power.

  2. The eye.

    can distinguish between objects very close together. In fovea region, cones closer together, than rods and cones in other parts of retina, i.e. most sensitive part of retina. Colour vision Trichromatic theory - thought to be 3 types of cones corresponding to the three primary colours, blue, green, red (max.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work