GS One‑Liners

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# Question & Answer
4101
What are the types of electric charge? - Positive and Negative
4102
What is electric charge? - Property of matter that causes it to experience force in an electric field, measured in Coulombs (C)
4103
How is chromatic aberration minimized? - Using combination of convex and concave lenses (achromatic doublet)
4104
What is chromatic aberration? - Dispersion of colors causing blurred image in lenses
4105
What is the role of lenses in correcting vision? - They adjust the focal point of light on the retina
4106
What is the principle behind optical fibers? - Total internal reflection of light within a core with higher refractive index
4107
What is the focal length of a lens or mirror? - Distance between the optical center and the focus, where parallel rays converge
4108
How does a telescope form a magnified image? - Objective lens forms real image, eyepiece lens magnifies it for observation
4109
How does a compound microscope form a magnified image? - Image formed by objective lens acts as object for eyepiece lens, producing a virtual, enlarged image
4110
What is a telescope? - Instrument to observe distant objects, can be refracting (lenses) or reflecting (mirrors)
4111
What is a microscope? - Optical instrument to view small objects, uses combination of objective and eyepiece lenses
4112
How are vision defects corrected? - Myopia: concave lens; Hypermetropia: convex lens; Astigmatism: cylindrical lens; Presbyopia: bifocal lens
4113
What are common defects of vision? - Myopia (nearsightedness), Hypermetropia (farsightedness), Presbyopia, Astigmatism, Cataract
4114
What is the human eye’s structure? - Cornea, lens, iris, retina, optic nerve
4115
Why does the sun appear red at sunrise and sunset? - Longer path through atmosphere scatters blue light, leaving red light
4116
Why is the sky blue? - Due to Rayleigh scattering, shorter wavelengths (blue) scatter more than longer wavelengths
4117
What is scattering of light? - Deviation of light by particles in the atmosphere, causing sky color and reddish sunsets
4118
How is a rainbow formed? - By refraction, reflection, and dispersion of sunlight in raindrops
4119
What is dispersion of light? - Separation of white light into constituent colors due to different refractive indices
4120
What is magnification? - Ratio of image height to object height, $M = h’/h = v/u$
4121
What is the lens formula? - $1/f = 1/v – 1/u$
4122
What are concave and convex lenses? - Convex lens converges light; Concave lens diverges light
4123
What is the mirror formula? - $1/f = 1/v + 1/u$, where f is focal length, v is image distance, u is object distance
4124
What are concave and convex mirrors? - Concave: curved inward; Convex: curved outward
4125
Name some applications of TIR. - Optical fibers, periscopes, binoculars, prisms in cameras