SPH 3U

Optics Review

  1. A ray of light travelling through air and entering glass at an oblique angle will

a)speed up onlyd)bend away from the normal only

b)slow down onlye)slow down and bend toward the normal

c)bend toward the normal only

  1. If do is the distance of the object from a lens, di is the distance of the image from the lens, and f is the focal length, the height of the image can be calculated by multiplying the height of the object by the ratio

a)do / did)di / do

b)f /doe)do / f

c)f / di

  1. A line is drawn perpendicular to the surface of a concave mirror. Such a line is called

a)the angle of incidenced)the path of light from the image

b)the centre of curvaturee)the normal at that point on the mirror

c)the principal focus

  1. A light ray travelling parallel to the principal axis of a concave mirror hits the mirror. It will be

a)reflected through the principal focusd)refracted through the optical centre

b)refracted through the principal focuse)reflected back along its original path

c)reflected through the centre of curvature

  1. When a ray of light travels from glass to air at an angle of incidence of 0, most of the light

a)travels straight throughd)reflects at an angle of reflection of 90

b)bends away from the normale)reflects straight back

c)bends towards the normal

  1. Which of the following statements is not correct for a simple magnifying glass?

a)The image is virtual. d)The lens is concave (diverging).

b)The image is erect. e) The object is placed inside the focus of the lens.

c)The image is larger.

  1. A distant object is slowly brought from a great distance toward the centre of curvature of a concave mirror. The image will

a)remain virtual and become smallerd)remain real and become smaller

b)remain virtual and become largere)remain real and become a point

c)remain real and become larger

  1. Which one of the following characteristics does not apply to the image formed by a concave (diverging) lens? The image is:

a)virtuald)located between the lens and its focal point

b)invertede)smaller than the object

c)located on the same side of the lens as the object

  1. Where must an object be placed with respect to a convex (converging) lens in order to obtain a virtual image?

a)at the principal focus

b)at twice the focal length

c)at a distance greater than twice the focal length

d)between the principal focus and the lens

e)between the principal focus and twice the focal length

  1. If a ray of light in air is incident on a plane glass surface at an angle of 45, the angle of refraction will be

a)equal to the angle of incidenced)equal to the angle of reflection

b)less than the angle of reflectione)independent of the angle of reflection

c)greater than the angle of incidence

  1. A small light source is in the bottom of an aquarium filled with water. A ray of light from the source makes an angle of 30.0 to the vertical and passes through a layer of carbon disulphide, (index of refraction 1.62), a layer of glass, (index of refraction 1.50), and then into the air. Assume that all the surfaces are horizontal.

a)Sketch the path of light through the layers, including the angles.

b)What is the angle of refraction of the light once it reaches the air?

  1. You are underwater looking up at a pole sticking up from the ground. You estimate that the pole is 5 m long. Explain, using a diagram, why your estimation is incorrect.
  1. Draw a scaled ray diagram to show

a)The image of an 18 cm high object that is 35 cm in front of a convex (converging) lens with a focal length of 30 cm. Include dimensions.

b)What is the height of the image for the preceding question?

c)The image for an 18 cm high object that is 15 cm in front of a concave (converging) mirror with a focal length of 20 cm. Include dimensions.

  1. Explain how the human eye can see the image on this paper. Start with “light from the ceiling fixtures reflects off the paper and then…”

From the textbook:

  1. Chapt. 9 Review (p. 360) #1, 3, 4, 5, 7, 9, 22
  2. Chapt. 10 Review (p. 398) #1, 2, 3, 4, 7, 8, 17, 19
  3. Chapt. 11 Review (p. 438) #5, 9, 21

OR

  1. Unit Review (p. 445) #1, 3, 4, 5, 9, 12, 14, 16, 20, 21, 22, 27b, 29, 30 , 48, 60, 65, 66

Answers:1. e)2. d)3. e)4. a)5. a)6. d)7. c)8. b)9. d)10. b)

11. b) 41.712. you will estimate it as being longer (the opposite as if you were looking into water)

13. b) – 108 cm

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