This article is related to Chapter Light of Science Fact File Book 2 for Secondary classes. Through 20 essential definitions and 100 concise Q&A sessions, it offers a comprehensive exploration of topics ranging from reflection to the electromagnetic spectrum. Whether you’re a student or an enthusiast, this provides invaluable insights into the fundamental nature of light.
Few important definitions from Chapter Light:
Few important definitions from Chapter Light are as follows:
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Light:
Light is a form of electromagnetic radiation that is visible to the human eye and enables us to perceive color, shape, and depth in our surroundings.
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Luminous objects:
Luminous objects are those that emit light of their own, such as the Sun, stars, or light bulbs.
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Non-luminous objects:
Non-luminous objects do not emit light on their own but can be seen by reflecting light from a luminous source. Examples include the Moon, planets, and most everyday objects.
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Opaque:
Opaque materials do not allow light to pass through them, preventing the transmission of light. These materials completely absorb or reflect light, making objects behind them invisible.
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Transparent:
Transparent materials allow light to pass through them easily, enabling objects on the other side to be clearly visible. Examples include glass and clear plastic.
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Translucent:
Translucent materials allow some light to pass through them but scatter or diffuse the light, making objects on the other side appear blurred or obscured. Examples include frosted glass and wax paper.
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Diffraction:
Diffraction is the bending of light waves around obstacles or through openings, causing them to spread out and produce patterns of light and dark fringes.
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Reflection:
Reflection occurs when light waves bounce off a surface, such as a mirror, and change direction. This phenomenon allows us to see objects by the light they reflect.
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Refraction:
Refraction is the bending of light as it passes from one medium to another, such as from air to water or from air to glass. This bending causes the direction of light to change, leading to phenomena like the bending of a pencil in water.
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Pigments:
Pigments are substances that selectively absorb and reflect certain wavelengths of light, giving objects their color. Common pigments include those found in paints, inks, and dyes.
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Spectrum:
The spectrum refers to the range of colors produced when white light is dispersed, typically seen as a continuum of colors from red to violet, as in a rainbow or when light passes through a prism.
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Dispersion:
Dispersion is the separation of white light into its component colors as it passes through a medium like a prism, due to each color having a different wavelength and thus bending at different angles.
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Convex lens:
A convex lens is thicker in the middle than at the edges and converge light rays, causing them to come together at a focal point. It can form real or virtual images depending on the object distance.
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Concave lens:
A concave lens is thinner in the middle than at the edges and diverge light rays, causing them to spread out. It forms only virtual images and cannot project real images.
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Prism:
A prism is a transparent optical element with flat, polished surfaces that refract and disperse light, separating it into its component colors. It’s often used in experiments or to create rainbows.
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Mirage:
A mirage is an optical illusion caused by atmospheric refraction, where light bends due to temperature gradients, creating false images of distant objects, such as water appearing on a hot road.
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Apparent depth:
Apparent depth is the perceived depth of an object or image as seen through a refractive medium, such as water or glass, which can make objects appear closer or farther than they actually are.
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Real depth:
Real depth is the actual distance or depth of an object, unaffected by the medium through which it is viewed, such as in air or vacuum.
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Rainbow:
A rainbow is a meteorological phenomenon caused by the dispersion, refraction, and reflection of sunlight in water droplets, resulting in a spectrum of colors appearing in the sky.
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Plane Mirror:
A plane mirror is a flat, smooth surface that reflects light rays without distorting them. It forms virtual images that are laterally inverted but maintain the same size and distance as the object being reflected. These mirrors are commonly used in everyday applications such as mirrors in bathrooms, dressing rooms, and periscopes.
Quizzes related to Chapter Light:
Solve these quizzes to learn more about this topic.
Short Questions and Answers related to Light:
Here are short questions and answers of the chapter Light:
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What can light travel through?
Answer: Transparent materials.
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What is an example of a translucent material?
Answer: Greaseproof paper.
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How does light travel?
Answer: In a straight line at high speed.
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What is the scientific term for a flat mirror?
Answer: Plane.
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In what direction do rough surfaces reflect light?
Answer: In all directions.
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Is light a form of electromagnetic radiation?
Answer: Yes.
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What is the main source of light on Earth?
Answer: The Sun.
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Do luminous objects emit their own light?
Answer: Yes.
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Do non-luminous objects emit light?
Answer: No.
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What are stars considered as in terms of light emission?
Answer: Luminous sources.
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What about planets and moons?
Answer: Non-luminous objects.
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What happens to light when it strikes opaque materials?
Answer: It gets absorbed.
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Name two translucent materials.
Answer: Greaseproof paper and frosted glass.
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How are light rays reflected on a flat surface like a mirror?
Answer: In the same direction.
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Is light faster than sound?
Answer: Yes, by a factor of one million.
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How can light rays be represented on a diagram?
Answer: By straight lines.
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How are angles measured when light reflects off a mirror?
Answer: Between the rays and a line drawn at 90 degrees to the mirror, called the normal.
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What is the property of materials through which light can pass?
Answer: Transparency.
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Give an example of an opaque material.
Answer: Metal.
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Which material allows some light to pass through but scatters it in different directions?
Answer: Translucent material.
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What happens to light when it enters a denser medium from a rarer one?
Answer: It slows down.
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What type of surfaces scatter light?
Answer: Rough surfaces.
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Can light travel through a vacuum?
Answer: Yes.
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How do we call the bending of light as it passes through different substances?
Answer: Refraction.
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What is the unit of measurement for the wavelength of light?
Answer: Nanometers.
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Which part of the eye controls the amount of light entering?
Answer: The iris.
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How are light waves affected when they pass through a narrow slit?
Answer: They spread out.
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What determines the color of an opaque object?
Answer: The wavelengths of light it absorbs.
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Which electromagnetic waves have the highest energy?
Answer: Gamma rays.
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What type of reflection occurs when light reflects off a rough surface?
Answer: Diffuse reflection.
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Which celestial bodies reflect light rather than emit it?
Answer: Moons.
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What causes the phenomenon of total internal reflection?
Answer: Light traveling from a denser to a rarer medium at an angle greater than the critical angle.
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What is the term for the bending of light around corners or edges?
Answer: Diffraction.
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What happens to light when it enters a medium with a higher refractive index?
Answer: It bends towards the normal.
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What is the process of converting light energy into chemical energy in plants called?
Answer: Photosynthesis.
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What is the phenomenon where light appears to bend as it passes through layers of air with different temperatures?
Answer: Mirage.
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Which type of mirror always forms an inverted image?
Answer: Concave mirror.
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How is the speed of light affected when it travels through a medium other than a vacuum?
Answer: It decreases.
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What is the term for the separation of light into its component colors due to a change in velocity?
Answer: Dispersion.
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What is the name for the colored circle that appears when white light is passed through a prism?
Answer: Spectrum.
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What is the concept of the fastest traveling entity compared to light?
Answer: Nothing can travel faster than light.
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What is the standard unit used to measure the speed of light?
Answer: Meters per second (m/s).
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Which color of light possesses the longest wavelength?
Answer: Red.
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What alteration occurs to the speed of light when it transitions from air to water?
Answer: Decreases.
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What form of reflection arises when light bounces off a smooth surface at the same angle it strikes it?
Answer: Regular reflection.
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What effect does a prism have on white light?
Answer: Splits it into its component colors.
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In which medium does light propagate the fastest?
Answer: Vacuum.
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What phenomenon describes the bending of light upon transitioning between substances?
Answer: Refraction.
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Among radio waves, infrared, visible light, and ultraviolet, which has the highest energy?
Answer: ultraviolet.
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What are the primary colors of light in the RGB color model?
Answer: Red, Green, Blue.
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Which optical process involves atoms absorbing light and subsequently emitting it in various directions?
Answer: Absorption.
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What object appears black due to absorbing all colors of light?
Answer: Black sweater.
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What term describes the bending of light waves around obstacles or openings?
Answer: Diffraction.
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In the formation of a rainbow, which color typically appears on the outer edge?
Answer: Violet.
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What is the term for the angle at which light is entirely reflected?
Answer: Critical angle.
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Among air, water, glass, and vacuum, where does light travel slowest?
Answer: Glass.
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What phenomenon refers to the alteration in light direction upon transitioning between mediums?
Answer: Refraction.
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Which scientist is renowned for experiments with light, prisms, and color?
Answer: Isaac Newton.
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Which lens type converge light rays, capable of forming real or virtual images?
Answer: Convex lens.
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What happens to white light when it passes through a prism?
Answer: Dispersion into its component colors.
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What is the scientific term for light bouncing off a surface?
Answer: Reflection.
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Which part of the eye regulates the amount of light entering?
Answer: Pupil.
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When light travels from a denser to a rarer medium, what happens to its speed?
Answer: Increases.
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Which color is produced by combining red and green light in the additive color model?
Answer: Yellow.
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What is the term for the bending of light as it passes around the edge of an obstacle?
Answer: Diffraction.
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What is the speed of light in a vacuum?
Answer: 300,000 km/s.
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Which part of the electromagnetic spectrum has wavelengths longer than visible light?
Answer: Infrared.
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What type of mirror always forms a virtual, upright, and diminished image?
Answer: Convex mirror.
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What is the process called when light separates into colors as it passes through prism?
Answer: Dispersion.
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What phenomenon makes the sky appear blue as light bends around small particles?
Answer: Rayleigh scattering.
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What unit measures the frequency of light waves?
Answer: Hertz (Hz).
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What causes a pencil to appear bent when partially submerged in water?
Answer: Refraction.
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What does “bioluminescence” refer to in the context of light?
Answer: Light emitted by living organisms.
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Which color appears opposite to orange in the color spectrum?
Answer: Violet.
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What type of lens diverge light rays and forms virtual images?
Answer: Concave lens.
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What is the term for the bending of light waves around the edges of an obstacle?
Answer: Diffraction.
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What is the primary function of the retina in the human eye?
Answer: Detect and process light signals.
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Which type of electromagnetic waves has the shortest wavelength?
Answer: Gamma rays.
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Where is the image located when light passes through a convex lens and forms a real image?
Answer: Behind the lens.
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Which color is seen when white light bends the least through a prism?
Answer: Red.
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What occurs when light rays spread out after passing through a narrow slit?
Answer: Diffraction.
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Which eye component focuses light onto the retina?
Answer: Lens.
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What is the process of producing light by passing an electric current through a gas?
Answer: Luminescence.
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Which waves in the electromagnetic spectrum have frequencies lower than radio waves?
Answer: Infrared.
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What color is obtained by mixing blue and green light?
Answer: Cyan.
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How does the wavelength of light change when it moves from air into glass?
Answer: Increases.
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What is the term for the bending of light waves due to a change in speed when passing between media?
Answer: Refraction.
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Which celestial body emits its own light?
Answer: Star.
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What color is produced by mixing red and blue pigments?
Answer: Purple.
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What is the angle of incidence for light undergoing total internal reflection?
Answer: Critical angle.
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