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(i) A mobile phone lies along the I principal axis of a concave mirror. Show with the help of a suitable diagram, the formation of its image. Explain whymagnification is not a uniform, (ii) Suppose the lower half of the concave mirror's reflecting surface is covered with an opaque material. What effect this will have on the image of the object?

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A convex lens of focal length 30 cm is placed coaxially with a convex mirror of radius of curvature 20 cm. The two are kept at 15 cm from each other. A point object lies 60 cm in front of the convex lens. Draw a ray diagram to show the formation of the image by the combination. Determine the nature and position of the image

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A convex lens of focal length 20 cm is placed coaxially with a concave mirror of focal length 10 cm at a distance of 50 cm apart from each other. A beam of light coming parallel to the principal axis is incident on the convex lens. Find the position of the final image formed by this combination. Draw the ray diagram showing the formation of the

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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Define power of a lens. Write its units. Deduce the relation `1/f=1/f_1+1/f_2` for two thin lenses kept in contact

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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You are given three lenses `L_1,L_2 and L_3` each of focal length 10 cm. An object is kept at 15 cm in front of `L_1` as shown. The final real image is formed at the focus `I` of `L_3` . Find the separation between `L_1, L_2 and

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A convex lens made up of a glass of refractive index 1.5 is dipped in turn in (i) a medium of refractive index 1.65 (ii) a medium of refractive index 1.33 (a) Will it behave as a converging lens or a diverging lens in the two cases? (b) How will its focal length change in the two

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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Use the mirror equation to show that (i) An object placed between `f` and `2f` of a concave mirror produces a real image beyond `2f`. (ii) A convex mirror always produces a virtual image independent of the location of the object. (iii) An object placed between the pole and focus of a concave mirror produces a virtual and enlarged

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A converging lens has a focal length of 20 cm in air. It is made of a material of refractive index 1.6. It is immersed in a liquid of refractive index 1.3. Calculate its new focal

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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Find the position of the image formed of the object O by the lens combination given in the

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State the necessary conditions for producing total internal reflection of light. Draw ray diagrams to show how specially designed prisms make use of total internal reflection to obtain inverted image of the object by deviation of rays (i) through 90° and (ii) through

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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With the help of a suitable ray diagram, derive a relation between the object distance (u), image distance (v) and radius of curvature R for the convex spherical surface when a ray of light travels from a rarer to denser

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A ray of light is incident on one face of a glass prism and emerges out from the other face. Trace the path of the ray and derive an expression for refractive index of the glass

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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The image obtained with a convex lens is erect and its length is four times the length of the object. If the focal length of the lens is 20 cm, calculate the object and image

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A convex lens is used to obtain a magnified image of an object on a screen 10 cm from the lens. If the magnification is 19, find the focal length of the

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(i) How is the focal length of a spherical mirror affected when the wavelength of the light used is increased? (ii) A convex lens has 20 cm focal length in air. What is its focal length in water? (Refractive index of air-water = 1.33, refractive index of air-glass =

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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(i) How is the focal length of a spherical mirror affected when it is immersed in water? (ii) A convex lens has 10 cm focal length in air. What is its focal length in water? (Refractive index of air-water = 1.33, refractive index of air-glass =

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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An object of 3 cm height is placed at a distance of 60 cm from a convex mirror of focal length 30 cm. Find the nature, position and size of the image

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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An object of 2 cm height is placed at a distance of 30 cm from a convex mirror of focal length 15 cm. Find the nature, position and size of the image

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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(i) With the help of a suitable ray diagram, derive the mirror formula for a concave mirror. (ii) The near point of a hypermetropic person is 50 cm from the eye. What is the power of the lens required to enable the person to read clearly a book held at 25 cm from the

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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Three light rays, red (R) green (G) and blue (B) are incident on a right angled prism AB C at face AB. The , refractive indices of the material of the prism for red, green and blue wavelengths are 1.39, 1.44 and 1.47 respectively. Out of the three, which colour of ray will emerge out of face AC? Justify your answer. Trace the path of these rays after passing through face

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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