3.2. Light
A subsection of Physics, 5054, through 3. Waves
Listing 10 of 242 questions
shows a ray of white light incident on a glass prism. P Q white red violet glass prism (not to scale) Refraction causes the white light to separate into different colours. Define the term ‘angle of refraction’. The angle of incidence of the white light as it enters the prism is 40° and the angle of refraction for the red light is 25°. Calculate the refractive index of the glass for red light. Show your working. refractive index = Using , state and explain how the refractive index for red light differs from the refractive index for violet light. The source of white light used in produces other types of electromagnetic radiation as well as visible light. State the name of the invisible radiation found at P and the invisible radiation found at Q. at P at Q
5054_s22_qp_22
THEORY
2022
Paper 2, Variant 2
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Ultraviolet radiation is one component of the electromagnetic spectrum. State the name of two components of the electromagnetic spectrum that have a smaller wavelength than ultraviolet radiation. State one useful application of ultraviolet radiation. Exposure to ultraviolet radiation from the Sun damages the eyes. State one type of damage to the eye caused by ultraviolet radiation. shows a ray of light. The ray passes into a semi-circular block of glass at A and leaves the glass at B, travelling along the surface to C. 40° A B C State the name given to the angle of incidence marked as 40°. Calculate the refractive index of the glass. refractive index =
5054_s23_qp_22
THEORY
2023
Paper 2, Variant 2
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shows a ray of light passing through the edge of a converging lens. 40o 25o converging lens normal Describe what happens to the direction of the ray of light as it enters and leaves the lens. State what happens to the speed, frequency and wavelength of the light as it enters the lens. Calculate the refractive index of the glass used in the lens. The focal length of the lens is 20 cm. An object is placed 50 cm from the lens and an image is formed on a screen. Explain what is meant by the focal length of a lens. You may draw a diagram if you wish. Draw a ray diagram to scale to show the formation of the image. The image is real. State two other properties of the image.
5054_w07_qp_2
THEORY
2007
Paper 2, Variant 0
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10 A student goes for a walk in the mountains. During a storm, she sees lightning strike a hillside in the distance. Several seconds later, she hears the thunder caused by the lightning. Explain why she hears the thunder several seconds after she sees the lightning. The student knows the distance to the hillside. She waits for lightning to strike the hillside again. Describe how she can determine a value for the speed of sound in air. After the storm, the student sees a rainbow. State the speed of light in air. speed = Calculate the wavelength in air of light of frequency 7.5 × 1014 Hz. wavelength = State the colours of the spectrum in order of increasing wavelength. In the laboratory, the student sends blue light into a glass prism placed on a sheet of paper. The arrangement is shown in . 45° blue light The blue light enters the prism with an angle of incidence of 45°. On , mark the angle of refraction in the glass and label it r. The student wishes to determine the angle of refraction. On the sheet of paper, she draws the path the ray takes in the glass. Describe how she could do this. 1. State the formula that relates the angle of incidence i, the angle of refraction r and the refractive index n. 2. The angle of refraction in the glass is 28°. Calculate the refractive index of the glass. refractive index = The student sends a ray of red light to the glass prism along the same path as the blue light. On , mark the path taken by the red light after it enters the prism.
5054_w13_qp_21
THEORY
2013
Paper 2, Variant 1
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State the speed of light in air. shows a ray of blue light passing from air into a glass block and refracting at the surface. glass block blue light (not to scale) As the light enters the glass, state what happens to 1. the speed of the light, 2. the frequency of the light, 3. the wavelength of the light. On , mark and label the angle of incidence i and the angle of refraction r. The refractive index of glass for blue light is 1.5. A ray of blue light strikes the surface of a glass block at an angle of incidence of 89°. Calculate the angle of refraction of the light in the block. angle of refraction = Explain why the angle of refraction of blue light in glass is always less than 45°. Blue light, travelling in air, strikes the side of a different glass block and continues in the same direction as it enters the glass block. shows the ray of light and the shape of the glass block. The critical angle for this glass is 42°. 45° blue light Explain why the light continues in the same direction as it enters the glass block. On , complete the path of the light until it leaves the glass.
5054_w14_qp_22
THEORY
2014
Paper 2, Variant 2
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Questions Discovered
242