Assertion: Planets are much closer to Earth, so unlike distant stars they are seen as extended sources of light.
Reason: The chapter states that the human eye is like a telescope because its lens system forms an image on a light-sensitive screen called the retina.
Assertion: Planets are much closer to Earth, so unlike distant stars they are seen as extended sources of light.
Reason: The chapter states that the human eye is like a telescope because its lens system forms an image on a light-sensitive screen called the retina.
Assertion: Particles of larger size scatter light of longer wavelengths.
Reason: A suitable Concave lens corrects hypermetropia by providing the additional focusing power needed to form the image on the retina.
Assertion: Particles of larger size scatter light of longer wavelengths.
Reason: A suitable Concave lens corrects hypermetropia by providing the additional focusing power needed to form the image on the retina.
Assertion: The Earth's atmosphere is described as A pure vacuum.
Reason: Light-sensitive cells in the retina are activated by illumination and generate electrical signals that are sent to the brain.
Assertion: The Earth's atmosphere is described as A pure vacuum.
Reason: Light-sensitive cells in the retina are activated by illumination and generate electrical signals that are sent to the brain.
Assertion: The lower portion of a common bifocal lens is convex and facilitates near vision.
Reason: The chapter explains that droplets refract and disperse sunlight, then reflect it internally, and finally refract it again as it emerges.
Assertion: The lower portion of a common bifocal lens is convex and facilitates near vision.
Reason: The chapter explains that droplets refract and disperse sunlight, then reflect it internally, and finally refract it again as it emerges.
Assertion: Elongation of the eyeball can cause myopia.
Reason: The chapter identifies an elongated eyeball as another cause of myopia.
Assertion: Elongation of the eyeball can cause myopia.
Reason: The chapter identifies an elongated eyeball as another cause of myopia.
Assertion: When ciliary muscles are relaxed, the lens becomes thin and its focal length increases, enabling clear vision of distant objects.
Reason: Activity 10.1 instructs the learner to look for the images of pins P and Q through the other face AC.
Assertion: When ciliary muscles are relaxed, the lens becomes thin and its focal length increases, enabling clear vision of distant objects.
Reason: Activity 10.1 instructs the learner to look for the images of pins P and Q through the other face AC.
Assertion: Contraction of the ciliary muscles increases the curvature of the lens, making it thicker.
Reason: The chapter states that a triangular glass prism has two triangular bases and three rectangular lateral surfaces.
Assertion: Contraction of the ciliary muscles increases the curvature of the lens, making it thicker.
Reason: The chapter states that a triangular glass prism has two triangular bases and three rectangular lateral surfaces.
Assertion: Continuous atmospheric refraction changes the apparent direction of starlight, making the star appear slightly higher than its actual position near the horizon.
Reason: The electrical signals generated by light-sensitive cells are sent to the brain Via the cornea.
Assertion: Continuous atmospheric refraction changes the apparent direction of starlight, making the star appear slightly higher than its actual position near the horizon.
Reason: The electrical signals generated by light-sensitive cells are sent to the brain Via the cornea.
Assertion: Very fine particles scatter mainly Red light only, according to the chapter.
Reason: For parallel refracting surfaces in a glass slab, the emergent ray is parallel to the incident ray but slightly laterally displaced.
Assertion: Very fine particles scatter mainly Red light only, according to the chapter.
Reason: For parallel refracting surfaces in a glass slab, the emergent ray is parallel to the incident ray but slightly laterally displaced.
Assertion: The chapter lists acute leukaemia among conditions that make a person ineligible to donate eyes.
Reason: If a planet is considered a collection of many point-sized sources, variations in light from the individual sources average out, nullifying twinkling.
Assertion: The chapter lists acute leukaemia among conditions that make a person ineligible to donate eyes.
Reason: If a planet is considered a collection of many point-sized sources, variations in light from the individual sources average out, nullifying twinkling.
Assertion: The Iris forms the transparent bulge on the front surface of the eyeball and is the entry path for light.
Reason: Planets are much closer to Earth and are seen as extended sources, so fluctuations from their many point-sized components average out.
Assertion: The Iris forms the transparent bulge on the front surface of the eyeball and is the entry path for light.
Reason: Planets are much closer to Earth and are seen as extended sources, so fluctuations from their many point-sized components average out.
Assertion: The chapter states that very fine particles mainly scatter blue light, while larger particles scatter light of longer wavelengths.
Reason: The activity asks learners to fix two more pins at P and Q so their line aligns with the images of P and Q.
Assertion: The chapter states that very fine particles mainly scatter blue light, while larger particles scatter light of longer wavelengths.
Reason: The activity asks learners to fix two more pins at P and Q so their line aligns with the images of P and Q.
Assertion: The eye-donation section says that people operated for cataract can still donate their eyes.
Reason: The chapter describes atmospheric refraction as the refraction of light by the Earth's atmosphere.
Assertion: The eye-donation section says that people operated for cataract can still donate their eyes.
Reason: The chapter describes atmospheric refraction as the refraction of light by the Earth's atmosphere.
Assertion: Ciliary muscles can modify the curvature of the eye lens.
Reason: Changing their action changes the curvature of the lens.
Assertion: Ciliary muscles can modify the curvature of the eye lens.
Reason: Changing their action changes the curvature of the lens.
Assertion: Air molecules and other fine particles scatter shorter-wavelength blue light more strongly than longer-wavelength red light, making the clear sky appear blue.
Reason: In a common bifocal lens, the lower portion consists of a Concave lens that facilitates near vision.
Assertion: Air molecules and other fine particles scatter shorter-wavelength blue light more strongly than longer-wavelength red light, making the clear sky appear blue.
Reason: In a common bifocal lens, the lower portion consists of a Concave lens that facilitates near vision.
Assertion: Ciliary muscles contract when the eye looks at a nearby object.
Reason: Their contraction increases the curvature of the eye lens.
Assertion: Ciliary muscles contract when the eye looks at a nearby object.
Reason: Their contraction increases the curvature of the eye lens.
Assertion: Newton's observation that the separated colours could recombine into white light led to the idea that Sunlight contains only red light.
Reason: A too-small eyeball is one of the causes of hypermetropia listed in the chapter.
Assertion: Newton's observation that the separated colours could recombine into white light led to the idea that Sunlight contains only red light.
Reason: A too-small eyeball is one of the causes of hypermetropia listed in the chapter.
Assertion: The iris controls the size of the pupil, which regulates the amount of light entering the eye.
Reason: At the second surface AC, light passes from glass into air and bends Towards the normal.
Assertion: The iris controls the size of the pupil, which regulates the amount of light entering the eye.
Reason: At the second surface AC, light passes from glass into air and bends Towards the normal.
Assertion: The chapter states that eye removal is a simple process and does not lead to any disfigurement.
Reason: Stars are very distant, so they approximate point-sized sources of light for this explanation.
Assertion: The chapter states that eye removal is a simple process and does not lead to any disfigurement.
Reason: Stars are very distant, so they approximate point-sized sources of light for this explanation.
Assertion: Rabies is specifically listed among conditions that prevent eye donation.
Reason: Planets are much closer to Earth and appear as extended sources, so variations from many point-sized sources average out.
Assertion: Rabies is specifically listed among conditions that prevent eye donation.
Reason: Planets are much closer to Earth and appear as extended sources, so variations from many point-sized sources average out.
Assertion: The human eye is like a camera.
Reason: Its lens system forms an image on a light-sensitive screen called the retina.
Assertion: The human eye is like a camera.
Reason: Its lens system forms an image on a light-sensitive screen called the retina.
Assertion: If Earth had no atmosphere, there would be no atmospheric scattering, so the sky would look dark.
Reason: The chapter states that Acute leukaemia patients can also donate eyes.
Assertion: If Earth had no atmosphere, there would be no atmospheric scattering, so the sky would look dark.
Reason: The chapter states that Acute leukaemia patients can also donate eyes.
Assertion: The Iris provides the finer adjustment of focal length required to focus objects at different distances on the retina.
Reason: Atmospheric refraction bends starlight towards the normal and makes a star near the horizon appear slightly higher than its actual position.
Assertion: The Iris provides the finer adjustment of focal length required to focus objects at different distances on the retina.
Reason: Atmospheric refraction bends starlight towards the normal and makes a star near the horizon appear slightly higher than its actual position.
Assertion: A decreased focal length helps the eye see nearby objects clearly.
Reason: The lens becomes thicker when the ciliary muscles contract for near vision.
Assertion: A decreased focal length helps the eye see nearby objects clearly.
Reason: The lens becomes thicker when the ciliary muscles contract for near vision.
Assertion: A suitable concave lens corrects myopia by bringing the image of a distant object back onto the retina.
Reason: The figure legend identifies ∠D as the angle of deviation.
Assertion: A suitable concave lens corrects myopia by bringing the image of a distant object back onto the retina.
Reason: The figure legend identifies ∠D as the angle of deviation.
Assertion: The chapter states that Violet light bends the least through a prism, while violet bends the most.
Reason: A myopic eye has a far point nearer than infinity and cannot see distant objects distinctly.
Assertion: The chapter states that Violet light bends the least through a prism, while violet bends the most.
Reason: A myopic eye has a far point nearer than infinity and cannot see distant objects distinctly.
Assertion: Suspended particles of Wooden chips are listed among the minute particles in the atmosphere.
Reason: The incident ray is the ray entering the prism from air at the first refracting surface.
Assertion: Suspended particles of Wooden chips are listed among the minute particles in the atmosphere.
Reason: The incident ray is the ray entering the prism from air at the first refracting surface.
Assertion: The chapter notes that danger signal lights are Blue.
Reason: Newton could not split the spectrum colours into any more colours using another similar prism.
Assertion: The chapter notes that danger signal lights are Blue.
Reason: Newton could not split the spectrum colours into any more colours using another similar prism.
Assertion: The chapter states that the time difference between actual sunset and apparent sunset is about 2 minutes.
Reason: The retina is described as a dark muscular diaphragm behind the cornea. It controls the size of the pupil.
Assertion: The chapter states that the time difference between actual sunset and apparent sunset is about 2 minutes.
Reason: The retina is described as a dark muscular diaphragm behind the cornea. It controls the size of the pupil.
Assertion: A convex lens is converging and has Negative focal length, so its optical power is positive.
Reason: Figure 10.4 labels ∠D as the angle of deviation.
Assertion: A convex lens is converging and has Negative focal length, so its optical power is positive.
Reason: Figure 10.4 labels ∠D as the angle of deviation.