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Academic Year: 2018/2019 – Term 3

Physics - Grade 9

Revision sheet

Chapter 13: section 1,2,3

pages: (442-462)

Spherical curved mirror: a mirror that has the shape of part of spheres surface .

Two types of spherical mirrors:

1- Concave spherical mirror : a mirror whose reflecting surface is a segment of

the inside of a sphere

-Called converging mirror (real focal point )

C: center of curvature , F: focal point , R: radius of curvature ,f: focal

length

R=2*f

-Real image : an image that is formed by the intersection of light rays ;a real

image can be projected on a screen

2. Convex spherical mirror : a mirror whose reflecting surface is a segment of

the outside of a sphere

- Called diverging mirror (virtual focal point )

-Virtual image : an image from which light rays appear to diverge , and the

virtual image can't be projected on a screen

For spherical mirrors ,three reference rays are used to find the image point

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______ 1. Part of a pencil that is placed in a glass of water appears bent in relation to

the part of the pencil that extends out of the water. What is this

phenomenon called?

a. interference c. diffraction

b. refraction d. reflection

______ 2. The _______________ of light can change when light is refracted because

the medium changes.

a. frequency c. speed

b. color d. transparency

______ 3. What distinguishes a real image from a virtual image?

a. Real images are inverted, whereas virtual images are upright.

b. Real images can be displayed on a surface, whereas virtual images

cannot.

c. Real images can be larger or smaller than the object, whereas virtual

images are equal in size to the object.

d. Real images are possible with any type of mirror, whereas virtual

images only occur with flat mirrors.

______ 4. For a spherical mirror, the focal length is equal to _______________ the

radius of curvature of the mirror.

a. one-fourth

b. one-half

c. twice

d. the square of

Rules Description Diagram

When an incident ray travels

parallel to the principal axis, it is

reflected through the focus (F).

When an incident ray passes

through the centre of curvature

(C), it is reflected back onto

itself.

When an incident ray passes

through the focus (F), the

reflected ray is parallel to the

principal axis.

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______ 5. An object is located in front of a concave spherical mirror between the

center of curvature (C) and the focal point (F). Where is the image

located?

a. behind the mirror

b. between the mirror and the focal point

c. between the focal point and the center of curvature

d. beyond the center of curvature

______ 6. Which of the following best describes the image produced by a flat

mirror?

a. virtual, inverted, and magnification greater than one

b. real, inverted, and magnification less than one

c. virtual; upright, and magnification equal to one

d. real, upright, and magnification equal to one

Q1: Define the following :

Normal :

…………………………………………………………………………………………

…………………………………………………………………………………………

Incidence angle

:………………………………………………………………………………….

…………………………………………………………………………………………

Concave mirror :

………………………………………………………………………….

…………………………………………………………………………………………

Q2: Typical wavelengths of visible light colors are listed below

violet blue green orange-yellow red

420 *109 m 450*109 m 550*1011 m 600*109 m 700*109 nm

a. Calculate the frequency of the electromagnetic waves that carry these

colors.

b. How does frequency change when wavelength increases?

__________________________________________________________________

c. Does the speed of light in air depend on frequency? on wavelength?

__________________________________________________________________

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Q3: Complete the following

1. The visible light spectrum sits between the _________ and __________

regions of the electromagnetic spectrum.

2. As the frequencies of the pure spectral colors increase, the wavelengths of the

colors___________.

3. The angle of the incoming light ray _____________ the reflected angle of

light

4. A ______________ mirror has a flat surface. Reflection is not distorted.

5. Which portion of the electromagnetic spectrum is used in a

television___________________________

6. Which portion of the electromagnetic spectrum is used in a microscope

_____________

7. Luminous flux ____________as the square of the distance from the source

increase .

Q4:

1. What type of reflection is illustrated in the figure shown above?

__________________

2. What type of image do flat mirrors always form?_____________________

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Q5: Yellow-green light has a wavelength of 560 nm. What is its frequency?

Q6: Order the following electromagnetic waves from the longest wavelength to

shortest wavelength

Radio waves / ultraviolet radiation / visible light /

infrared radiation

_____________ / __________________ / ______________ / ____________

Q7: Consider the diagram at the right in answering the next three

questions.

1. The angle of incidence is denoted by angle .

2. The angle of reflection is denoted by angle .

3. If an incident ray of light makes an angle of 35°

with the mirror surface then the angle of

reflection is °.

Q8: Draw a ray diagram for a 5 cm long candle located 10 cm in front of a flat

mirror. On the drawing, be sure to label object, image, object distance (p), and image

distance (q).

And list three characteristic of the image in the flat mirror

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Q9. A 1.0 cm tall object is placed 6.0 cm away from a concave mirror that has a 4.0

cm focal length.

a. Where will the image be located? (use the mirror equation to find distance)

b. Draw a ray diagram below to locate the image

Q10. Label the curved mirror using page

Q11. A concave shaving mirror has a focal length of 30cm.

a. Calculate the image position of a 10 cm tall cologne bottle placed

in front of the mirror at a distance of 15 cm.

b. Calculate the magnification of the image.

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c. Is the image real or virtual?

d. What is the height of the image in the mirror?

Q12. An object is located 25 cm in front of a concave mirror. If the mirror has a

focal length of 15 cm, where will the image be located?

Q13. Complete the following ray diagram and then list the image properties.

Q14. Red light has a wavelength of 450 nm , what is frequency?

Image properties

1.

2.

3.

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Q15. Complete the ray diagram for the two cases below.

A- If the object is located "beyond" the center of curvature. Description of Image:

Location:

_________________________________

O: Upright or Inverted

S: Magnified or Reduced

T: Real or Virtual B- If the object is located at the center of curvature.

Description of Image: Location:

___________________________________

O: Upright or Inverted

S: Magnified or Reduced

T: Real or Virtual

Case 3: If the object is located

Q16. True or false :

1. _________________ Rays perpendicular to the principal axis of a concave

mirror converge at or near the focal point.

2. ________________ The focal length of a concave mirror is half the radius of

curvature of the mirror.

3. _________________ Concave mirrors can produce only virtual images.

4. _________________ Concave mirrors cannot act as magnifiers.

5. _________________ The focal point of a convex mirror is behind the mirror.

6. _________________ Rays reflected from a convex mirror always converge.

7. _________________ The images produced by convex mirrors are real images.

8. _________________ Compared to the size of the objects, the images

produced by convex mirrors are always the same size.