LIGHT2003

1. The diagram shows a student looking at a plane mirror.

The image observed by the student is

2. The diagram shows the fringe pattern produced from Young's double slit experiment using the monochromatic red light source.

W h a t h a pp e n s t o t h e f r i ng e s i f monochromatic yellow light source is used?A The bright fringes are wider than the dark fringesB The dark fringes are wider than the bright fringesC The distance between consecutive fringes decreaseD The distance between consecutive fringes increase

3. The diagram shows a light ray travelling from air into a glass prism.

What is the critical angle of the glass? A 40° D 70°B 50° E 90°C 600

4. Which of the following shows total internal reflection?

5. The diagram shows the design of a simple astronomical telescope.The focal length of the lens P is fP and the focal length of lens Q is fQ

Which statement is correct?A fP is shorter than fQB The power of lens P is higher than lens QC The image of lens P is real whereas the image of lens Q is virtualD The image magnification is the ratio of fQ to fp

Plane mirror

6. The diagram shows a cross-section of a fibre optic cable.

Which comparison is correct? A Density of P < density of Q B Density of P > density of Q C Density of P = density of Q

7. Which graph represents the sound wave in the highest pitch?

A

B

8. The diagram shows an arrangement of apparatus for light diffraction experiment.

Which diffraction pattern appears on the screen?

20049. An observer cannot see the coin in an empty glass as shown in Figure (i).

However, he can see the coin when the glass is filled with water as shown in Figure (ii)

The observer can see the coin in Figure (ii) due to

A the total internal reflection of lightB the refraction of lightC the reflection of lightD the diffraction of light

10. The d iagram shows l ight ray XO experiencing total internal reflection when travelling from glass to air.

Which statements about total internal reflection are correct?

P — 0 is more than the critical angle of glassQ — The speed of light in glass is higher than in airR — The refractive index of glass is greater than air

A P and QB P and R C Q and RD P, Q and R

11. The diagram shows Ahmad and Salim standing in front of a plane mirror at a distance of 5 m and 3 m respectively.

What is the distance of Ahmad's image as seen by Salim?

A 2m D 8mB 5m E 11m

C 6m

12. The diagram shows a light ray with an incident angle of 5° being reflected by a plane mirror MN. The mirror is then rotated clockwise through an angle of 15°.

What is the new angle of reflection of the light ray? A 5° C 15°

B 10° D 20°

13. The diagram shows an object which is placed at u cm from the centre of a convex

lens. The focal length of the lens is 20 cm.

Which of the following characteristics of the image is not correct when u is 10 cm, 15 cm, 35 cm and 45 cm from the lens?

U /cm Characteristics of the image A 10 Virtual and bigger

B 15 Virtual and bigger C 35 Real and smaller

D 45 Real and smaller

14. A timekeeper for a sprint event starts the stopwatch as he sees the smoke from the pistol instead of hearing the shot.This action is taken because

A sound produces echoesB light travels in a straight lineC light travels faster than soundD surrounding temperature affects the speed of sound

15. A system is oscillating at its natural frequency without damping.What happens to the total energy of the oscillating system?

A It remains constantB It decreasesC It increases

200516. The diagram shows a boy appearing shorter hen he is in a swimming pool. The

depth of the water in the pool is 1.2 m. The refractive index of water is 1.33.

What is the apparent depth of the pool?A 0.1 m D 1.1 mB 0.3 m E 1.6 m 0.9 m

17. The diagram shows a light ray directed into a glass block.Which is the angle of refraction?

18. The diagram shows an object placed in front of a concave mirror. The distance of the object is less than the focal length, f, of the mirror.

What are the characteristics of the image formed?A Real, upright, bigger than objectB Real, inverted, smaller than object C Virtual, upright, bigger than objectD Virtual, inverted, smaller than object

19. The diagram shows a light ray, P, directed into a glass block. The critical angle of the glass is 42°.In which direction does the light move from point Q?

20. A student draws light rays passing through lenses, P, Q, R and S as shown in the diagram below. F is the focal point of lenses P, Q, R and S.

Which drawing shows the correct path of the light rays?

A II onlyB I and III onlyC I, II and IV onlyD I, II, III and IV

200621. Diagram 13 shows two cars, P and Q, travelling in the opposite

directions,passing through a sharp bend.

Which mirror is the most suitable to be placed at X so that the river in car P can see car Q?

22. Diagram 14.1 and Diagram 14.2 show light rays travelling from glass to air at different incident angles.

Which angle is the critical angle of the glass?A p C rB q D s

23. Diagram 15 shows the path of light travelling from air into liquid X.

What is the refractive index of X? A 0.17 D 1.50B 0.68 E 2.00 C 1.46

24. Diagram 16 shows the formatin of the image of an object by a convex lens.

If the height of the object is 2 cm, what is the height of the image?

A 6.50 cm D 3.25 cmB 4.50 cm E 2.25 cm C 4.00 cm

25. Diagram 17 shows Ali taking an eye test. The distance between Ali and the plane mirror is 1 m. Ali sees the image of the object in the mirror.

If the distance between the image and Ali is 5 m, calculate the distance between Ali and the object.

A 2m C 4mB 3m D 8m

200725 Diagram 25 shows a boy standing in front of a plane mirror.

Diagram 25

The boy moves 1 m backwards.Calculate the distance between the boy and his image.A 3 m

B 4 mC 6 mD 8 m

2 6 Diagram 26 shows the path of light from P to O.

Diagram 26

The critical angle of water is 48'. If 0' 48°, which is the correct path of light after passing through point 0?

A O RB O S

C O TD O U

27 Diagram 27

shows a ray of light passing into a glass block. The refractive index of the glass is 1-54.

D i a g r a m 2 7

2 8 Which of the

following ray

diagrams is correct

for a

magnifying glass?

Section A

2003

1 Diagram 1 shows a mother observing the legs of her son in the pool. His legs appear to be shorter because of a light phenomenon.

Diagram 1(a) (i) Name the light phenomenon involved.

___________________________________________________________

[1 mark]

(ii) Explain how this phenomenon occurs.

___________________________________________________________

___________________________________________________________

[2 marks]

(iii) In Diagram 2, draw a ray diagram from point P to the eye to show how the legs appear shorter.

Diagram 2[2 marks]

(b) The depth of water is 0.4 m.Calculate the distance of the image of the foot at point P from the surface of the water. [Refractive index of water = 1.33]

[2 marks]

20042 Diagram 2 shows in image of letters FIZI when viewed through a glass of

water.

Diagram 2

(a) State the light phenomenon that causes the image of FIZI to be enlarged.

___________________________________________________________

[1 mark]

(b) What is the change in size of the image if the water is replaced with a transparent liquid of a greater density?

___________________________________________________________

[1 mark]

(c) The glass of water is replaced with a lens M with focal length of 10 cm. The distance between the book cover and the centre of the lens is 8 cm.It is observed that the image FIZIK is enlarged.(i) Name the type of lens M.

___________________________________________________________

[1 mark]

(ii) Calculate the distance of the image from lens M.

[2 marks](iii) In the space below sketch a ray diagram to show how the image is

formed.

[2 marks]

20053 Diagram 3.1 shows a student standing 3 m from a plane mirror in a room.

The student can see the image of the wall clock located 2 m behind him.

Diagram 3.1

Diagram 3.2 shows the top view of the student in the room.

(a) Name the light phenomenon that enables the student to see the image of the wall clock in the plane mirror.

___________________________________________________________

[1 mark]

(b)What is the distance between the student and the image of the wall

clock?

___________________________________________________________

[1 mark]

(c)The student then moves 1 m towards the plane mirror. What is the distance between the student and the image of the wall clock?

___________________________________________________________

[1 mark]

Diagram 3.2

(d)The time shown by the wall clock is 9 a.m.By drawing the hands of the clock in Diagram 3.3, complete the image of the wall clock in the plane mirror as seen by the student.

[1 mark]

(e)The student moves to position X. He can see the image of the lamp in the

plane mirror. In Diagram 3.4, draw a ray diagram to show how the student

can see the image of the lamp.

[2 marks]

Diagram 3.3

Wall clock

Diagram 3.4

20064 Diagram 4.1 shows a submarine equipped with an optical instrument P

Diagram 4.2 shows the structure of the optical instrument P

(a) Name the optical instrument P

___________________________________________________________

[1 mark]

(b) In Diagram 4.2, two glass prisms must be placed so that the object can be seen by the observer. The position of one of the glass prisms is as shown.(i) In box A in Diagram 4.2, draw and shade the second prism.

[1 mark]

(ii) Explain why the prisms in optical instrument P are placed as in 4(b)

(i).

___________________________________________________________

___________________________________________________________

[2 marks]

(c) (i) In Diagram 4.2, complete the path of the light ray from the object to the observer's eye.

[1 mark](ii) State one characteristic of the image observed.

___________________________________________________________

[1 mark]

(d) The refractive index of the glass prism is 1.52. Calculate the critical angle of the glass prism.

[2 marks]

20075 Diagram 5.1 and Diagram 5.2 show a light ray passing through prism P an

prism Q , respectively.Prism P and prism Q are made of glass with different densities.

Prism P Prism Q

(a) What is meant by critical angle ?Tick ( √) the correct answer in the box provided.

The angle of incidence when the angle of refraction is 90 °The angle of incidence when the incident ray is totally reflected.

[1 mark]

(b) Explain why the light ray does not bend when it enters both prisms at point A.

…………………………………………………………………………………[1 mark]

(c) (i) Based on Diagrams 5.1 and Diagrams 5.2 , how can the angle of incidence at point B be made equal to the critical angle?

Prism P

………………………………………………………………………………..

Prism Q

………………………………………………………………………………..

[2 marks]

Diagram 5.1 Diagram 5.2

(ii) Diagram 5.1 shows the light ray passing from glass to air at point B.Compare the density of glass with the density of air

………………………………………………………………………………

[1 mark](iii) Based on Diagram 5.1 and Diagram 5.2 , what happen to the light

ray after passing point B ?

Diagram 5.1

………………………………………………………………………………

Diagram 5.2

………………………………………………………………………………

[2 marks]

(d) Name the phenomenon shown in Diagram 5.2

…………………………………………………………………………………………[1 mark]

Section B20046 Diagram 6.1. and 6.2 show the parallel rays of light directed toward the curved

mirrors, J, K and K. CP is the radius of curvature, and F is the focal point of the mirrors.

Curved mirror J Curved mirror K

Diagram 6.1 Diagram 6.2

(a) What is meant by focal point?[1 mark]

(b) Using Diagram 6.1 and 6.2, compare the curvanture of mirrors J and K and the effects on reflected rays.State the relationship between the curvanture of the mirrors and their focal lengths.

[5 marks](c) Diagram 6.3 shows a cross section of a parabolic reflector used in a car

headlamp. The headlamp has two bulbs, X and Y. Bulb X is located at the focal point of the reflector while bulb Y is above bulb X.

Diagram 6.2Explain what happens to the light rays from the bulb when only:(i) bulb X is switched on, (ii) bulb Y is switched on.You may use diagrams to illustrate your answers.

[4 marks]

(d) You are given two pieces of plane mirror measuring 5 cm x 6 cm to make a periscope.(i) Using these mirrors and other materials, describe how you would

make the periscope. [4 marks]

(ii) Explain why the image observed through the periscope using plane mirrors are not very clear.

[2 marks]

(iii) Suggest modification that can be made to the periscope to produce clearer and bigger images.

[4 marks]

2006

7 Diagram 7.1 and Diagram 7.2 show the light rays from two identical objects passing through the convex lenses, J and K. Both the lenses produce virtual images. F is the focal point for each lens.

Diagram 6.1

Diagram 7.2

(a) (i) What is meant by virtual image?[1 mark]

(ii) With reference to Diagram 7.1 and Diagram 7.2, compare the thickness of the lenses, the focal length and the size of image produced by the lenses J and K.Relate the size of the image with the focal length to make a deduction regarding the relationship between the power of the lens and the focal length.

[5 marks](b) Explain why a piece of paper burns when placed under a convex lens aimed

towards hot sun rays.[4 marks]

(c) You are given two convex lenses, P and Q, with focal lengths 40 cm and 5 cm respectively. Both the lenses are used to build a simple astronomical telescope at normal adjustment.(i) Using the two lenses, explain how you are going to build the simple

astronomical telescope.[6 marks]

(ii) Suggest modifications that need to be done on the telescope to produce clearer and bigger images.

[4 marks]

Section C

8. (a) Diagram 8.1 shows two convex lenses, R and S, used in an astronomical telescope. The focal length for R is 40 cm and for S is 10 cm.

(i) Define the power of a lens.[1 mark]

(ii) Give two reasons why R is used as the objective lens of the telescope.

[2 marks](iii) Using lenses R and S, draw a ray diagram of Diagram 8.1 to show the

formation of the final image by the telescope at normal adjustment. Use a scale of 10 cm to 1 cm.

[5 marks]

(iv) Calculate the magnification of the final image formed by the telescope at normal adjustment.

[2 marks](b) Presbyopia is an inability of the eye to adjust the focussing of far and

near objects. This usually happens when we get old, where the ciliary muscles is less able to change the shape of the eye lens to focus the image on the retina, as shown in Diagram 8.2 and 8.3.

As an optician, you have three designs of lenses, X, Y and Z, in your shop. The cross-section of X, Y and Z are shown in Diagram 8.4.

Diagram 8.1

Diagram 8.2 Diagram 8.3

(i) Choose the most suitable design of lens in Diagram 8.4 to correct the sight of a person with presbyopia and explain the suitability of the design.

(ii) Explain why the other two designs are not suitable. Either low or high refractive index glass can be used to make the lenses.

(iii) Which type of glass is not suitable to make the lens chosen in (b)(i)? Give reasons for your choice.

[10 marks]

Diagram 8.4