Exam Questions: Reflection + Reflection Practical Flashcards
A man is wearing mirrored sunglasses. Anyone looking at him can see their own reflection in the glasses but cannot see his eyes. The man can see through the glasses. Describe what happens to the light as it passes from the surroundings to the mirrored sunglasses. (2)
Some light will transmit through the glasses and will reach his eyes. The man’s eyes will register the light and therefore he can see through the glasses (1)
The rest of the light is reflected and that light is what everyone else registers so they cannot see through the glasses (1)
A man is wearing mirrored sunglasses. One of the lenses has been covered in tiny scratches. Describe how the reflective properties of the [un/damaged] lenses are different: what effect will it have on the reflective images produced by the lenses (3)
The dangers lens has a rough surface so it will reflect light in many diff. directions (diffuse reflection) – 1 mark
Therefore no clearly reflected image will be seen in the damaged lens – 1 mark
A clear reflection is seen in the undaunted lens because light is reflected in a single direction by a smooth surface (specular reflection) – 1 mark
A student has set up the apparatus for the required practical– reflection. He has shone the light at a mirror and measure the angles of incidence and reflection. The smallest angle the protractor can measure is 1 degree. The markings on the protractor is 1 cm apart. The student sets the ray box to shine beams of light at 0.9 cm. How does this improve results? (3)
The beam is narrower than the markings on the protractors scale so it will be easier to measure angles to the nearest degree – 1 mark
So it’s less likely that they will be human errors made due to judgment – 1 mark
This means their results are more accurate – 1 mark
The student has finished the reflection practical and has drawn his results up on a graph with a line of best fit. There is a problem though, not all his points line up to the line of best fit. What happened and what went wrong in the practical? (2)
The angle of incidence does not match up with the angle of reflection and this does not agree with the laws of reflection – 1 mark
In his practical, the normal is line is possibly not perpendicular to the mirror (not set up at 90 degrees) or a human error was made – 1 mark
A student was investing the reflection of light by diff. types of surfaces. She set up a ray box, a mirror and a piece of white card (so the ray will shine to the mirror and will be reflected to the paper). Name the type of reflection observed at the mirror than at the card.
At the mirror its a specular reflection and at the paper card it’s a diffuse reflection
A student shone a beam of light towards a piece of paper and observed its reflective properties. They found that the surface of the card was rough. What was the student’s final observation on reflective properties?
They should’ve found that the light would’ve reflected in different directions and scattered everywhere. this is a diffuse reflection. It happens because the light hits the surface at many diff. angles so normal is different for each ray shone at the paper.
A student set up the practical for investigating reflection. They used a ray box for the practical. Explain why and what could they have used instead?
A ray is used to produced a thin beam of light so that the angles of incidence and reflection could be easily and accurately measured. A laser could’ve been used to produce similar results
