Q29.The radius of curvature of each surface of a convex lens having refractive index 1 . 8 is 20 cm. The lens is now immersed in a liquid of refractive index 1 . 5. The ratio of power of lens in air to its power in the liquid will be ๐ฅ: 1. The value of ๐ฅ is
What This Question Tests
This question evaluates the application of the Lens Maker's Formula to calculate the power of a lens in air and when immersed in a liquid, requiring a ratio calculation.
Concepts Tested
Formulas Used
1/f = (ฮผ_lens/ฮผ_medium - 1)(1/Rโ - 1/Rโ)
P = 1/f
๐ NCERT Sections This Tests
9.7 โ Double-Convex Lenses Are To Be Manufactured From A Glass Of
Physics Class 12 ยท Chapter 9
9.7 Double-convex lenses are to be manufactured from a glass of refractive index 1.55, with both faces of the same radius of curvature. What is the radius of curvature required if the focal length is to be 20cm?
9.8 โ A Beam Of Light Converges At A Point P. Now A Lens Is Placed In The
Physics Class 12 ยท Chapter 9
9.8 A beam of light converges at a point P. Now a lens is placed in the path of the convergent beam 12cm from P. At what point does the beam converge if the lens is (a) a convex lens of focal length 20cm, and (b) a concave lens of focal length 16cm?
9.3 โ A Tank Is Filled With Water To A Height Of 12.5 Cm. The Apparent
Physics Class 12 ยท Chapter 9
9.3 A tank is filled with water to a height of 12.5 cm. The apparent depth of a needle lying at the bottom of the tank is measured by a microscope to be 9.4 cm. What is the refractive index of water? If water is replaced by a liquid of refractive index 1.63 up to the same height, by what distance would the microscope have to be moved to focus on the needle again?
๐ Question Details
- Chapter
- Ray Optics
- Topic
- Lens Maker's Formula and Power of a lens
- Year
- 2023
- Shift
- 11 Apr Shift 1
- Q Number
- Q29
- Type
- Numerical
- NCERT Ref
- Class 12 Physics Ch 9: Ray Optics
More from this Chapter
Q64.An astronomical telescope has a large aperture to (1) reduce spherical aberration (2) have high resolution (3) increase span of observation (4) have low dispersion
Q65.If two mirrors are kept at 60โ to each other, then the number of images formed by them is (1) 5 (2) 6 (3) 7 (4) 8
Q66.Which of the following is used in optical fibres ? (1) total internal reflection (2) scattering (3) diffraction (4) refraction
Q65.To get three images of a single object, one should have two plane mirrors at an angle of (1) 60โ (2) 90โ (3) 120โ (4) 30โ