The law of reflection says the angle of incidence equals the angle of reflection, and the angle of incidence is measured to the normal, so this Year 8 sheet opens with the reflection law and its reference line. The answers add that refraction is light bending when it changes speed.
Key Takeaways
The angle of incidence equals the angle of reflection (Q1).
The angle of incidence is measured between the ray and the normal (Q2).
Q4 records the bending of light when it changes speed.
Section A: Multiple Choice Questions (1 Mark Each)
Choose the correct option for each question.
1.The law of reflection states that the angle of incidence...
(a) is always zero(b) equals the angle of reflection(c) is always twice the angle of reflection(d) is always greater than the angle of reflection
2.The angle of incidence is measured between the incident ray and the...
(a) real and upside down(b) virtual and the same size(c) real and larger(d) virtual and upside down
4.Refraction is the...
(a) bending of light when it changes speed(b) reflection of light off a mirror(c) absorption of light by a surface(d) emission of light by a bulb
5.When light travels from air into water it...
(a) bends away from the normal(b) bends towards the normal(c) travels in a straight line(d) stops completely
6.Which statement is true about the speed of light?
(a) light is fastest in glass(b) light is slowest in a vacuum(c) light is fastest in a vacuum(d) light travels at the same speed in all materials
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.State the law of reflection.
8.What is the normal in a reflection diagram?
9.Give three properties of the image formed by a plane mirror.
10.Explain why a straight straw appears bent when it is placed in a glass of water.
11.What happens to the speed of light when it enters a denser medium?
12.What is the difference between a real image and a virtual image?
13.Give one practical use of a plane mirror.
14.Explain why a fish in a pool appears to be at a shallower depth than it really is.
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.A light ray hits a plane mirror with an angle of incidence of 30°. Use the law of reflection to state the angle of reflection.
16.A light ray strikes a mirror at 40° to the mirror surface. The angle of incidence is measured from the normal, which is at 90° to the surface. Calculate the angle of incidence.
17.The angle of reflection of a ray is 25°. State the angle of incidence.
18.A ray makes an angle of 55° with the normal. It reflects so that the angle of reflection equals the angle of incidence. Calculate the angle between the incident ray and the reflected ray.
19.A ray hits a mirror with an angle of incidence of 30°. Calculate the angle between the incident ray and the reflected ray.
20.A light ray strikes a mirror at 20° to the surface. Hint: find the angle of incidence first, then add both angles from the normal. Calculate the angle between the incident ray and the reflected ray.
Answer Key
1. b) equals the angle of reflection
2. b) normal
3. b) virtual and the same size
4. a) bending of light when it changes speed
5. b) bends towards the normal
6. c) light is fastest in a vacuum
7. Refer to solution guide.
8. Refer to solution guide.
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20. Refer to solution guide.
End of Worksheet
People Also Ask
What does the law of reflection state?
The angle of incidence equals the angle of reflection, option (b) in this worksheet (Q1).
What is the angle of incidence measured between?
The incident ray and the normal, option (b) in this worksheet (Q2).
What is refraction?
The bending of light when it changes speed, option (a) in this worksheet (Q4).
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