Name: ______Class: ______Date: ______
Instructions: Write answers in the right-hand column. Score: ______/
Section A—Multiple choice
1 / Light travels with a speed at aboutA. 300,000 meters per second B. 3,000,000 meters per second
C. 30,000 kilometres per second D. 300,000 kilometres per second / 1
2 / Which of the Electromagnetic radiation (EMR) has the highest frequency?
A infrared light B radio waves
C X-rays D microwaves / 1
3 / Which of the following waves does not belong to electromagnetic radiation?
A infrared light B white light
C X-rays D sound waves / 1
4 / Which of the radiation is involved in scanning luggage at the airport?
A X-rays B microwaves C gamma rays D blue light / 1
5 / Blue skies and red sunsets are caused by the:
A dispersion of light B refraction of light
C absorption of light D scattering of light / 1
6 / Comparing microwaves and ultraviolet rays,
A microwaves have lower frequencies
B ultraviolet rays have longer wavelengths
C microwaves have more energy than ultraviolet rays
D ultraviolet rays are more visible than microwaves / 1
7 / The law of reflection is
A the angle of incidence equals the angle of reflection
B the angle of incidence is greater than the angle of reflection
C the angle of incidence is less than the angle of reflection
D the angle of incidence does not equal the angle of reflection
8 / Three primary colours of light which mix to make white light, they are:
A yellow, green, red B cyan, yellow, magenta
C green, blue, red D red, green, orange / 1
Section B—Written answers (60 marks)
1 / If a light ray strikes a mirror at an angle of 30o to the mirror, what is:a the angle of incidence?
b the angle of reflection? / a
b / 2
2 / What is meant by the refraction of light? / 2
3 / The diagram on the right shows a light ray travelling through air to the interface between the air and a glass block.
On the diagram, draw the normal, and a possible path for the ray in the glass.
Label on the diagram: normal, angle of incidence, angle of refraction, refracted ray, incident ray / / 4
4 / Curved mirrors are usually shown in
cross-sectional views to indicate their shapes. Three such shapes are shown below.
a Which mirror is which?
(parabolic, convex, concave )
b What happen when a spot light is placed in front of each of these mirrors?
c Give one use of each of these mirrors. / 9
5 / Is light always refracted when it passes from one material to another? Explain your answer. / 2
6 / a When do people use infrared camera or binoculars work?
b How does infrared camera work? / 3
7 / Explain why the sky appears blue during the day. / 2
8 / Complete the following table on EMR.
Radiation / Special Feature / Uses
microwave
just beyond the visible spectrum
radiowaves
shortest wavelength and the most powerful energy
visible
Using the following:
telecommunication, ultraviolet, cancer treatment, photosynthesis, cooking, longest wavelength and lowest frequency, only spectrum visible to human eye, wavelengths ranging from 1 mm to 1 m, sun tanning, gamma ray / 10