The force between two electric charges is related to Coulomb's law (option B). Coulomb's law is a fundamental principle in physics that explains the behavior of electrostatic forces between charged particles. It describes how the magnitude of the force between two point charges depends on the amountRead more
The force between two electric charges is related to Coulomb’s law (option B). Coulomb’s law is a fundamental principle in physics that explains the behavior of electrostatic forces between charged particles. It describes how the magnitude of the force between two point charges depends on the amount of charge on each object and the distance separating them. The law highlights that the electric force increases with larger charges and decreases with greater distances. This principle is essential for understanding various electrostatic phenomena, such as the attraction or repulsion between objects and the behavior of electric fields. Coulomb’s law differs from Ampere’s law (option A), which deals with magnetic fields generated by electric currents; Faraday’s law (option C), which relates to electromagnetic induction; and Ohm’s law (option D), which describes the relationship between voltage, current, and resistance in an electrical circuit.
The entire charge of a charged conductor remains on its outer surface (option B). This phenomenon occurs because of the repulsive forces between like charges. When a conductor is charged, the charges redistribute themselves in such a way that they are as far apart as possible to minimize repulsive fRead more
The entire charge of a charged conductor remains on its outer surface (option B). This phenomenon occurs because of the repulsive forces between like charges. When a conductor is charged, the charges redistribute themselves in such a way that they are as far apart as possible to minimize repulsive forces. This results in the charges moving to the outer surface of the conductor, creating an equilibrium state. Inside a conductor, the electric field is zero, so there is no force driving the charges to stay on the inner surface. This principle is fundamental to electrostatics and explains why the charges on a conductor reside entirely on the outer surface. Unlike insulators, where charges can remain stationary, conductors allow for the free movement of charges to achieve this state. Thus, the entire charge of a charged conductor resides on its outer surface.
When a glass rod is rubbed with silk, the rod becomes positively charged (option B). This happens due to the transfer of electrons between the two materials. Glass tends to lose electrons easily, while silk has a higher affinity for electrons. When they are rubbed together, electrons are transferredRead more
When a glass rod is rubbed with silk, the rod becomes positively charged (option B). This happens due to the transfer of electrons between the two materials. Glass tends to lose electrons easily, while silk has a higher affinity for electrons. When they are rubbed together, electrons are transferred from the glass rod to the silk. As a result, the glass rod is left with a deficiency of electrons, which makes it positively charged. The silk, having gained those electrons, becomes negatively charged. This process of charging by friction demonstrates the principle of electron transfer between materials with different tendencies to gain or lose electrons. This transfer creates a static charge on both objects, with the glass rod ending up positively charged due to the loss of electrons.
Light travels slower in glass than in air because the refractive index of air is less than the refractive index of glass (option A). The refractive index is a measure of how much light bends when it enters a material. Air, having a lower refractive index, allows light to travel through it with minimRead more
Light travels slower in glass than in air because the refractive index of air is less than the refractive index of glass (option A). The refractive index is a measure of how much light bends when it enters a material. Air, having a lower refractive index, allows light to travel through it with minimal interaction and minimal slowing down. In contrast, glass has a higher refractive index, meaning light encounters more resistance as it passes through. This resistance occurs because light interacts more with the atoms and molecules in the glass, which absorb and re-emit the light waves, effectively slowing their overall speed. While the density of the materials can influence their refractive properties, the primary reason for the difference in light speed is the refractive index, making light travel slower in glass than in air.
Fiber optic used in communication works only on the principle of total internal reflection of light (option D). Inside an optical fiber, light travels through a core made of a material with a high refractive index surrounded by a cladding with a lower refractive index. When light enters the core atRead more
Fiber optic used in communication works only on the principle of total internal reflection of light (option D). Inside an optical fiber, light travels through a core made of a material with a high refractive index surrounded by a cladding with a lower refractive index. When light enters the core at a certain angle (above the critical angle), it undergoes total internal reflection at the core-cladding interface. This reflection process traps the light within the core, allowing it to travel long distances without significant loss of signal strength. This principle is crucial for transmitting data as pulses of light, enabling high-speed and reliable communication over optical networks. Unlike regular reflection of light (option A) or diffuse reflection of light (option B), which do not maintain the coherence or intensity needed for optical communication, total internal reflection specifically facilitates the efficient transmission of light signals through optical fibers, making it indispensable in modern telecommunications infrastructure.
Light travels in optical fibers due to total internal reflection of light (option D). Total internal reflection is a phenomenon where light, upon encountering the boundary between two materials with different refractive indices, is reflected back into the denser material if it strikes the boundary aRead more
Light travels in optical fibers due to total internal reflection of light (option D). Total internal reflection is a phenomenon where light, upon encountering the boundary between two materials with different refractive indices, is reflected back into the denser material if it strikes the boundary at an angle greater than the critical angle. In optical fibers, which are typically made of a core surrounded by cladding with lower refractive index, light entering the core at an angle greater than the critical angle undergoes total internal reflection. This continuous reflection allows light to propagate through the fiber by bouncing off the core-cladding interface, even if the fiber bends. This property of total internal reflection enables optical fibers to transmit signals over long distances with minimal loss and interference. Unlike diffraction (option A), refraction (option B), or polarization (option C), total internal reflection is the specific optical phenomenon that facilitates the efficient transmission of light signals through optical fibers.
A magnifying lens is a convex lens (option C) that is thicker in the middle and thinner at the edges. This type of lens is designed to bend light rays inward, converging them to a focal point on the opposite side of the lens. When an object is placed within the focal length of the lens, a magnifiedRead more
A magnifying lens is a convex lens (option C) that is thicker in the middle and thinner at the edges. This type of lens is designed to bend light rays inward, converging them to a focal point on the opposite side of the lens. When an object is placed within the focal length of the lens, a magnified virtual image is formed on the opposite side. This magnification effect allows for easier viewing of small objects or details that are otherwise difficult to see with the naked eye. Magnifying lenses are commonly used in various applications such as magnifying glasses, microscopes, and cameras to enhance visual clarity and detail. Unlike plane-concave lenses (option A), concave lenses (option B), or cylindrical lenses (option D), convex lenses are specifically shaped to create magnification by focusing light rays to produce enlarged images.
Lambert's law relates to illumination (option D). It describes how light is absorbed by a material, specifically focusing on how the intensity of illumination (light) decreases as it passes through or interacts with a material. The law states that the amount of light absorbed by a material is directRead more
Lambert’s law relates to illumination (option D). It describes how light is absorbed by a material, specifically focusing on how the intensity of illumination (light) decreases as it passes through or interacts with a material. The law states that the amount of light absorbed by a material is directly proportional to the thickness of the material and the concentration of the absorbing substance within it. This principle is fundamental in various fields, including optics, photography, and materials science, where understanding how light interacts with and penetrates materials is crucial. Lambert’s law helps quantify how much light is absorbed, reflected, or transmitted through different media, influencing everything from the design of optical instruments to the development of materials with specific light absorption characteristics. Unlike reflection (option A), refraction (option B), or interference (option C), Lambert’s law specifically addresses the interaction of light with materials in terms of absorption and illumination.
A cylindrical lens (option A) is used to correct the defect of astigmatism. Astigmatism occurs when the cornea or lens of the eye is unevenly curved, causing blurred or distorted vision at both near and far distances. A cylindrical lens has different powers in different meridians, often correcting tRead more
A cylindrical lens (option A) is used to correct the defect of astigmatism. Astigmatism occurs when the cornea or lens of the eye is unevenly curved, causing blurred or distorted vision at both near and far distances. A cylindrical lens has different powers in different meridians, often correcting the irregular curvature of the eye by compensating for the specific directions of curvature that cause astigmatism. By selectively focusing light along one axis more than the other, the cylindrical lens helps to bring light rays from different directions into focus on the retina, resulting in clearer vision. This correction is distinct from the use of concave (option B) or convex lenses (option C), which are typically used to correct nearsightedness or farsightedness, respectively. Bifocal lenses (option D) are used to correct presbyopia, a condition where the eye loses its ability to focus on nearby objects due to aging.
To an astronaut in outer space, the sky appears black (option C). Unlike on Earth, where the atmosphere scatters sunlight and makes the sky appear blue during the day, outer space lacks an atmosphere to scatter light. As a result, when viewed from space, the sky appears dark and black. This darknessRead more
To an astronaut in outer space, the sky appears black (option C). Unlike on Earth, where the atmosphere scatters sunlight and makes the sky appear blue during the day, outer space lacks an atmosphere to scatter light. As a result, when viewed from space, the sky appears dark and black. This darkness extends in all directions, broken only by the presence of stars, planets, and other celestial bodies against the vast backdrop of space. The absence of atmospheric scattering also means that the astronaut can see the unfiltered light from distant stars and galaxies, offering a clear view of the universe beyond Earth’s atmosphere. Therefore, the sky appears black to astronauts in outer space, contrasting with the blue sky seen from the surface of Earth due to atmospheric effects.
The force between two electric charges is related to
The force between two electric charges is related to Coulomb's law (option B). Coulomb's law is a fundamental principle in physics that explains the behavior of electrostatic forces between charged particles. It describes how the magnitude of the force between two point charges depends on the amountRead more
The force between two electric charges is related to Coulomb’s law (option B). Coulomb’s law is a fundamental principle in physics that explains the behavior of electrostatic forces between charged particles. It describes how the magnitude of the force between two point charges depends on the amount of charge on each object and the distance separating them. The law highlights that the electric force increases with larger charges and decreases with greater distances. This principle is essential for understanding various electrostatic phenomena, such as the attraction or repulsion between objects and the behavior of electric fields. Coulomb’s law differs from Ampere’s law (option A), which deals with magnetic fields generated by electric currents; Faraday’s law (option C), which relates to electromagnetic induction; and Ohm’s law (option D), which describes the relationship between voltage, current, and resistance in an electrical circuit.
See lessThe entire charge of a charged conductor
The entire charge of a charged conductor remains on its outer surface (option B). This phenomenon occurs because of the repulsive forces between like charges. When a conductor is charged, the charges redistribute themselves in such a way that they are as far apart as possible to minimize repulsive fRead more
The entire charge of a charged conductor remains on its outer surface (option B). This phenomenon occurs because of the repulsive forces between like charges. When a conductor is charged, the charges redistribute themselves in such a way that they are as far apart as possible to minimize repulsive forces. This results in the charges moving to the outer surface of the conductor, creating an equilibrium state. Inside a conductor, the electric field is zero, so there is no force driving the charges to stay on the inner surface. This principle is fundamental to electrostatics and explains why the charges on a conductor reside entirely on the outer surface. Unlike insulators, where charges can remain stationary, conductors allow for the free movement of charges to achieve this state. Thus, the entire charge of a charged conductor resides on its outer surface.
See lessWhen a glass rod is rubbed with silk, the rod
When a glass rod is rubbed with silk, the rod becomes positively charged (option B). This happens due to the transfer of electrons between the two materials. Glass tends to lose electrons easily, while silk has a higher affinity for electrons. When they are rubbed together, electrons are transferredRead more
When a glass rod is rubbed with silk, the rod becomes positively charged (option B). This happens due to the transfer of electrons between the two materials. Glass tends to lose electrons easily, while silk has a higher affinity for electrons. When they are rubbed together, electrons are transferred from the glass rod to the silk. As a result, the glass rod is left with a deficiency of electrons, which makes it positively charged. The silk, having gained those electrons, becomes negatively charged. This process of charging by friction demonstrates the principle of electron transfer between materials with different tendencies to gain or lose electrons. This transfer creates a static charge on both objects, with the glass rod ending up positively charged due to the loss of electrons.
See lessLight travels slower in glass than in air, because
Light travels slower in glass than in air because the refractive index of air is less than the refractive index of glass (option A). The refractive index is a measure of how much light bends when it enters a material. Air, having a lower refractive index, allows light to travel through it with minimRead more
Light travels slower in glass than in air because the refractive index of air is less than the refractive index of glass (option A). The refractive index is a measure of how much light bends when it enters a material. Air, having a lower refractive index, allows light to travel through it with minimal interaction and minimal slowing down. In contrast, glass has a higher refractive index, meaning light encounters more resistance as it passes through. This resistance occurs because light interacts more with the atoms and molecules in the glass, which absorb and re-emit the light waves, effectively slowing their overall speed. While the density of the materials can influence their refractive properties, the primary reason for the difference in light speed is the refractive index, making light travel slower in glass than in air.
See lessFiber optic used in communication works only on which principle?
Fiber optic used in communication works only on the principle of total internal reflection of light (option D). Inside an optical fiber, light travels through a core made of a material with a high refractive index surrounded by a cladding with a lower refractive index. When light enters the core atRead more
Fiber optic used in communication works only on the principle of total internal reflection of light (option D). Inside an optical fiber, light travels through a core made of a material with a high refractive index surrounded by a cladding with a lower refractive index. When light enters the core at a certain angle (above the critical angle), it undergoes total internal reflection at the core-cladding interface. This reflection process traps the light within the core, allowing it to travel long distances without significant loss of signal strength. This principle is crucial for transmitting data as pulses of light, enabling high-speed and reliable communication over optical networks. Unlike regular reflection of light (option A) or diffuse reflection of light (option B), which do not maintain the coherence or intensity needed for optical communication, total internal reflection specifically facilitates the efficient transmission of light signals through optical fibers, making it indispensable in modern telecommunications infrastructure.
See lessIrrespective of the size of the optical fibre, light travels in it because it is a device through which signals can be transferred from one place to another. On which phenomenon is this based?
Light travels in optical fibers due to total internal reflection of light (option D). Total internal reflection is a phenomenon where light, upon encountering the boundary between two materials with different refractive indices, is reflected back into the denser material if it strikes the boundary aRead more
Light travels in optical fibers due to total internal reflection of light (option D). Total internal reflection is a phenomenon where light, upon encountering the boundary between two materials with different refractive indices, is reflected back into the denser material if it strikes the boundary at an angle greater than the critical angle. In optical fibers, which are typically made of a core surrounded by cladding with lower refractive index, light entering the core at an angle greater than the critical angle undergoes total internal reflection. This continuous reflection allows light to propagate through the fiber by bouncing off the core-cladding interface, even if the fiber bends. This property of total internal reflection enables optical fibers to transmit signals over long distances with minimal loss and interference. Unlike diffraction (option A), refraction (option B), or polarization (option C), total internal reflection is the specific optical phenomenon that facilitates the efficient transmission of light signals through optical fibers.
See lessWhat exactly is a magnifying lens?
A magnifying lens is a convex lens (option C) that is thicker in the middle and thinner at the edges. This type of lens is designed to bend light rays inward, converging them to a focal point on the opposite side of the lens. When an object is placed within the focal length of the lens, a magnifiedRead more
A magnifying lens is a convex lens (option C) that is thicker in the middle and thinner at the edges. This type of lens is designed to bend light rays inward, converging them to a focal point on the opposite side of the lens. When an object is placed within the focal length of the lens, a magnified virtual image is formed on the opposite side. This magnification effect allows for easier viewing of small objects or details that are otherwise difficult to see with the naked eye. Magnifying lenses are commonly used in various applications such as magnifying glasses, microscopes, and cameras to enhance visual clarity and detail. Unlike plane-concave lenses (option A), concave lenses (option B), or cylindrical lenses (option D), convex lenses are specifically shaped to create magnification by focusing light rays to produce enlarged images.
See lessWhat is Lambert’s law related to?
Lambert's law relates to illumination (option D). It describes how light is absorbed by a material, specifically focusing on how the intensity of illumination (light) decreases as it passes through or interacts with a material. The law states that the amount of light absorbed by a material is directRead more
Lambert’s law relates to illumination (option D). It describes how light is absorbed by a material, specifically focusing on how the intensity of illumination (light) decreases as it passes through or interacts with a material. The law states that the amount of light absorbed by a material is directly proportional to the thickness of the material and the concentration of the absorbing substance within it. This principle is fundamental in various fields, including optics, photography, and materials science, where understanding how light interacts with and penetrates materials is crucial. Lambert’s law helps quantify how much light is absorbed, reflected, or transmitted through different media, influencing everything from the design of optical instruments to the development of materials with specific light absorption characteristics. Unlike reflection (option A), refraction (option B), or interference (option C), Lambert’s law specifically addresses the interaction of light with materials in terms of absorption and illumination.
See lessWhich of the following lenses should be used to correct the defect of astigmatism?
A cylindrical lens (option A) is used to correct the defect of astigmatism. Astigmatism occurs when the cornea or lens of the eye is unevenly curved, causing blurred or distorted vision at both near and far distances. A cylindrical lens has different powers in different meridians, often correcting tRead more
A cylindrical lens (option A) is used to correct the defect of astigmatism. Astigmatism occurs when the cornea or lens of the eye is unevenly curved, causing blurred or distorted vision at both near and far distances. A cylindrical lens has different powers in different meridians, often correcting the irregular curvature of the eye by compensating for the specific directions of curvature that cause astigmatism. By selectively focusing light along one axis more than the other, the cylindrical lens helps to bring light rays from different directions into focus on the retina, resulting in clearer vision. This correction is distinct from the use of concave (option B) or convex lenses (option C), which are typically used to correct nearsightedness or farsightedness, respectively. Bifocal lenses (option D) are used to correct presbyopia, a condition where the eye loses its ability to focus on nearby objects due to aging.
See lessThe sky will appear to an astronaut in outer space as
To an astronaut in outer space, the sky appears black (option C). Unlike on Earth, where the atmosphere scatters sunlight and makes the sky appear blue during the day, outer space lacks an atmosphere to scatter light. As a result, when viewed from space, the sky appears dark and black. This darknessRead more
To an astronaut in outer space, the sky appears black (option C). Unlike on Earth, where the atmosphere scatters sunlight and makes the sky appear blue during the day, outer space lacks an atmosphere to scatter light. As a result, when viewed from space, the sky appears dark and black. This darkness extends in all directions, broken only by the presence of stars, planets, and other celestial bodies against the vast backdrop of space. The absence of atmospheric scattering also means that the astronaut can see the unfiltered light from distant stars and galaxies, offering a clear view of the universe beyond Earth’s atmosphere. Therefore, the sky appears black to astronauts in outer space, contrasting with the blue sky seen from the surface of Earth due to atmospheric effects.
See less