======Investigating the Law of Reflection======


<WRAP right box>
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**Safety: **{{$demo.safety_description}}\\
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**Alternative titles:** Measuring Angles of Incidence and Reflection
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====Summary====                   
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====Procedure====  
  -Place a sheet of plain A3 paper on the desk and draw a straight horizontal line across the middle.  
  -Use a protractor to draw a vertical line at right angles to the first line, labeling it “N” for normal.  
  -Place a plane mirror along the horizontal line so that the normal meets the mirror surface.  
  -Set up a ray box with a slit and lens to produce a single narrow ray of light.  
  -Shine the ray at the point where the normal meets the mirror to create an incident ray.  
  -Mark the path of the incident ray with a cross and the reflected ray with another cross.  
  -Remove the mirror and join the crosses with straight lines to show both rays.  
  -Measure the angle of incidence and the angle of reflection using a protractor.  
  -Repeat the experiment for several different angles of incidence.  
  -Record results in a table and compare the values.



====Links==== 
Investigating the law of reflection using a light box - Dr. Steve Griffiths: 
{{youtube>XM_UXUqo6ZM?}}\\

Law of Reflection using a light box - raftsj: 
{{youtube>EJe2wFQ4BgI?}}\\

📄 Reflection, refraction, and sound waves - OCR Gateway - BBC Bitesize: [[https://www.bbc.co.uk/bitesize/guides/zxk6v9q/revision/4]]\\

====Variations====
  *Test with different mirror types (plane, concave, convex).  
  *Change the color of the light using filters and see if results differ.  
  *Investigate reflection on different surfaces (metal, plastic, glass).



====Safety Precautions====
  *Ray box bulbs get hot—avoid touching directly and allow cooling before handling.  
  *Carry out the experiment in a dimmed room to see rays clearly; remove trip hazards beforehand.  
  *Avoid looking directly into the light beam.




====Questions to Consider====
  *What relationship should hold between the angle of incidence and angle of reflection? (They should be equal.)  
  *Why is it important to use a normal line? (It provides a reference point for measuring angles accurately.)  
  *How can repeated measurements improve the accuracy of the results? (They allow for averaging and identification of anomalies.)  
  *How does this experiment demonstrate the law of reflection? (Results consistently show incidence angle = reflection angle.)