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(d) 30cm
(a) A
(c) >
(c) a horse of less brightness
(d) 0
(b) same
(a) 2:3
(c) 1.414
(d) 4
(b) - 7.5 cm
(b) – 7.5 cm
The position to place an object to get a real image magnified twice in front of a magnifying lens of focal length 20 cm is at a distance of (from optical center)
(d) 30cm
(d) 30cm
See lessYou are given three media A, B and C of refractive index 1.33, 1.65 and 1.46. The medium in which the light will travel fastest is
(a) A
(a) A
See lessAn object of length l (<f) is placed along the axis between the focus and center of a concave mirror with one of its end at focus. The length of the image is
(c) >
(c) >
See lessLarge number of thin strips of black paint are made on the surface of a convex lens of focal length 20 cm to catch the image of a white horse. The image will be
(c) a horse of less brightness
(c) a horse of less brightness
See lessA concave mirror of radius 30 cm is placed in water. It’s focal length in air and water differ by
(d) 0
(d) 0
See lessSun glasses have zero power as the radius of curvature of the two surfaces is
(b) same
(b) same
See lessThe ratio of the wavelengths of a light wave travelling with a speed of 2 x 10⁸ and 3 x 10⁸ in different media is
(a) 2:3
(a) 2:3
See lessIf the critical angle for a medium is 45°, its refractive index will be
(c) 1.414
(c) 1.414
See lesslf four different colours of light fall parallel to the principal axis of a convex lens, the number of points of convergence on the axis will be
(d) 4
(d) 4
See lessAn object is placed at a distance of 30 cm from a concave lens of focal length 10 cm. The position of image from the optical centre is
(b) - 7.5 cm
(b) – 7.5 cm
See less