Home › UP Board Class 10 › Science › The Human Eye and the Colourful World › In a young eye, the focal length range of the ey…
In a young eye, the focal length range of the eye lens is approximately:
Answer & Solution
Correct answer: A.
1. The eyeball is ~2.3 cm in diameter, and the relaxed lens has focal length close to this so that infinity focuses on the retina.
2. Accommodation can shorten this slightly to focus near objects.
3. Hence the focal length is around 2.5 cm with a small downward adjustment range.
_Source: NCERT Class 10 Science, Ch 10 "The Human Eye and the Colourful World", §10.1_
Related questions
The apparent flattening of the Sun's disc at sunset is due to:A child cannot read words on the blackboard clearly. The likely defect and correction are:The image formed on the retina by the human eye is:Scattering of light is most pronounced when the wavelength of light is:Why must we hold a book about 25 cm away to read it comfortably?The eye lens is described as which type of biconvex structure?A 10-cm-tall object placed 30 cm in front of a 20-cm concave mirror has an image at:Why don't the planets twinkle but stars do?