• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6
7. 7
7
8. 8
8

# To investigate how the angle of deviation in a glass block depend on the angle of incidence.

Extracts from this document...

Introduction

Planning:

Simple procedure:

Make the light ray from the ray box pass through the glass block by changing the angle of incidence several times and measure the angle of deviation for each angle of incidence.

Apparatus:

Reading ranges: The range of angle of incidence will from 0° to 89°and  10°difference between them.

Safety: Wood board will be needed to prevent any fires by placing the bulb in the ray box too long on the table and heat the table up. Avoid our hands with touching the bulb directly and scald the skins.

Method: Use the above apparatus to see what the angle of deviation is when we have a particular angle of incidence. Repeat this by using different value of angles i.

Steps:

• Place a board on the table and put a piece of A3 paper on it.
• Place a glass block on the paper and draw its shape along its edges.
• Draw a normal line on the block frame on the paper.
• Draw the angle of incidence with a particular value.
• Switch on the ray box and make the light ray overlap the incidence ray.
• Draw the refracted ray that overlaps the light ray which is bent away the normal.
• Connect the incidence ray and refracted ray.
• Measure each angle of deviation which is relative each angle of incidence.
• Repeat the experiment and record different results.

(Measure all the angles by using a protractor.)

Valid Evidence:

• Vary angle of incidence (independent variable) by moving the ray box further away form the normal. After that I need to measure the angle of deviation by using a protractor.
• Control variables for  a fair test, I will have to keep the following factors the same:
1. Same glass block
2. Ray box distance from block (This can affects the width of light ray and the brightness as well)
3.  Use the same light box (Different light box may have different colors and brightness)
4. Ensure apparatus not knocked/moved during measurement (This makes our results will not be accurate)
• Simple Result Table & Simple diagram of general theory:

Middle

°

89°

Theory:

When the light ray travels from the fast medium (air) to the slow medium (glass block) its speed has decreased, wave frequency stays the same and the wavelength decreases. So parts of wave reaches boundary first and slows down which causes the change in direction. See diagram above.

Preliminary work:

Use a ray box with single slit to make the light ray through a rectangular glass block by changing the angle of incidence and measure the angle of relative refractions. (See the relative graph on the left and simple diagram on the right). My preliminary work also helped me to plan an accurate procedure: Avoid too many lines on the paper to prevent lines overlap each other. Avoid the range between each reading is too small to prevent the change of refraction angle is too small.Minimized the error by using long ruler to draw the lines.

From the graph, I can see the general pattern that as the angle of incidence increases, the angle of refraction increases but slowly at the large value of i. This enables me to make the following prediction.

Prediction:

As the angle of incidence increases, the angle of refraction increases, but more slowly. From the formula (d= i – r), i rises, r rises slowly, so d rises rapidly at large i.

Analysis:

Conclusion

Suitability of procedure:

I think my procedure is suitable, because we could make it fair test by keeping other variables constant. The results are enough and reliable.

Improvements:

• To do the experiment more times and gain more repeats to decrease the error
• To use narrower slit that makes the beam narrower to go through the block (incorporating focusing lens)
• To use larger glass block giving more accuracy on where light emerges, so the measurement error of angle deviation falls.

Accounting for anomaly:

The causes of anomaly in my results might be affected by this factor. Parallax error is caused especially wider beams at large angle of incidence. Possible chips on block can affect the track of refracted ray.

Even through my results have one anomaly, doesn’t affect the general conclusion. Because it still agreed with my prediction and the line on the graph is good enough. So the evidence is reliable enough to firmly definitely support my conclusion that as i increases d increases at an even greater rate.

Further Works:

We can investigate the same problem by using different ways.

1. Investigate by using single colour (Get d vs I graph for different colours of spectrum). Simple apparatus seen below

See how angle of deviation varies with angle of incidence each time.

1. Investigate deviation going from slow medium to fast medium (Simple apparatus below).
1. Use different material of block (E.g. Perspex)

This student written piece of work is one of many that can be found in our GCSE Waves 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

# Related GCSE Waves essays

1. ## Is Sunbathing Good?

4 star(s)

In this case, they should get advice from their physician to find out if the medication will make them UV-sensitive. Many people become addicted to tanning, which is unofficially known as Tanorexia. Some of the symptoms of Tanorexia include a false belief that he or she is too pale, and will therefore exceed the limits of UV exposure.

2. ## Investigate how the angle of refraction is affected by different inputs of the angle ...

3 star(s)

Snell's law is often stated in terms of the indexes of refraction of the two media rather than the speeds of light in the media. Refracted index = sine (i) - incidence ray sine (r) - refraction ray Total internal reflection: Waves going from a slower to a faster medium speed up and bend at the boundary, e.g.

1. ## Resonance of a Wine Glass

3 star(s)

I connected the oscilloscope to the power supply and adjusted the settings to my liking. I then attached the highly sensitive microphone to a jar of around the same height as the wine glass using selotape. Finally I selotaped the glass to the work area so as the distance between

2. ## Find a relationship between the angles of incidence and the angles of refraction by ...

This value is called the absolute refractive index, which is constant for a certain object. From the results table, it can be seen that the values for the absolute refractive index of the perspex is approximately 1.50, which is also the theoretical value for perspex.

1. ## Deviation of Light by a Prism.

the deviation, this means that every incident ray has in fact two angles of deviation, depending on which ray you choose to measure from. This is why the graph is shaped like it is, because there are two different angles of Incidence for each angle of Deviation.

2. ## Is the speed of sound affected when it travels threw different temperatures of air

According to this equation, sound travels at 331.4m/s at zero degrees Celsius. For every degree raise in temperature, the velocity increases by 0.6m/s. Materials Resonance tube apparatus water two tuning forks-different frequencies rubber hammer thermometer. Procedure 1. Raise the water supply cup to the top of the resonance so that water fills the glass tube.

1. ## SIGNAL ANALYSIS

C = 0.33?F The Laplace Transform for this filter is 1/(RCs + 1). Taking the poles to zero gives a cut off frequency of 10.26KHz. Table of Results: Frequency Output Voltage Output Decibels 500 0.4 -26.02 1000 0.7 -21.16 2000 1.4 -15.14 5000 3.4 -7.43 7000 4.3 -5.39 8000 4.7

2. ## Physics Case Study - Do Sunbeds Cause Skin Cancer?

o The lamps in sun-beds are becoming increasingly strong, putting out stronger and stronger rays, this is not monitored by any sort of safety agency, so overexposure is a likely danger. o There is no set age precautions made by the government, children as young as nine have been reported

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