The focal length of the piano – convex lens is 2R. Its radius of curvature is R then the refractive index of the material used is ………………
A) 2
B) 1.5
C) 1/2
D) 1
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The Convex lens behaves as a converging lens if it is kept in a medium with refractive index less than the refractive index of the lens.
B) Both statements are false
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A double convex lens has two surfaces of equal radii “R” and refractive index n = 1.5. The focal length is …………………..
Correct option is B) +R
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The refractive index of the glass which is symmetrical convergent lens if its focal length is equal
Correct option is C) 3/2
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The radii of curvature of a double convex lens are 10 cm and 10 cm. Its refractive index is 1.5. The focal length is ……………….
Correct option is A) 10 cm
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When a lens of focal length f is cut in to two equal halves perpendicular to principal axis, then the focal length of each part of the lens is ………………
Correct option is B) double
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A convex lens of focal length 20 cm is cut into two halves along principal axis then focal length of each part will be …………………
Correct option is A) 20 cm
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A convex lens of focal length 20 cm is cut into two halves perpendicular to the principal axis then focal length of each part will be ……………….
Correct option is C) 40 cm
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What are convex and concave lenses? For which condition, convex lens will have negative focal length?
1. A lens is said to be convex if it is thicker in the middle and narrowing towards the periphery. According to Cartesian sign convention, its focal length is positive. 2....
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A point object O is placed on the principle axis of a convex lens of focal length 10 cm at 12 cm from the lens.
U = -12 f = -10 1/v - 1/u = 1/f 1/v + 1/12 = 1/10 1/v = 1/60 \(-\frac{1}{v^2} \)dv or \(\frac{1}{u^2} \)du du = \(\frac{v^2}{u^2} \)du \( \frac{v}{u} \)= same path △u1 = △u2 = 1mm △u1 = △v2 △v2 = vf - vi x2 = △v2 + 1mm x2...
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Find the focal length of a convex mirror whose radius of curvature is 32 cm.
We have, f = \(\frac{f}{2}\) = \(\frac{32}{2}\) = 16 cm.
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