Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 1]PhysicsOptical Instruments

The focal length of a normal eye-lens is approximately

Options

  1. A1 mm
  2. B25 cm
  3. C1 m
  4. D2 cm

Correct answer

D. 2 cm

Step-by-step solution

The distance between the eye lens and the retina in a normal human eye is approximately 2 cm . For viewing distant objects, the object distance is u = - . Using the lens formula, 1 v - 1 u = 1 f Substituting v = 2 cm and u = - , we get 1 2 - 1 - = 1 f f = 2 cm Thus, the focal length of a normal eye-lens is approximately 2 cm .

Practice Optical Instruments on Quantrex Academy →

More from Optical Instruments

A person observes several trees in an open space, with the following details given. Arrange the trees in decreasing order of their apparent sizes. Tree Height (m) Distance from theWhen the image is formed at the near point ( 25 cm ) of a normal eye, a simple microscope exhibits a magnifying power of 3.0 . Calculate the magnifying power of this microscope if A child has a near point at 10 cm . Determine the maximum angular magnification the child can obtain using a convex lens of focal length 10 cm .When the image is formed at the near point ( 25 cm ) of a normal eye, a simple microscope exhibits a magnifying power of 3.0 . Determine the focal length of the microscope.An object is viewed using a simple microscope of focal length 12 cm . To obtain the maximum angular magnification, at what distance from the lens should the object be positioned? TA simple microscope is rated at 5 X for a normal relaxed eye. Determine its magnifying power for a relaxed farsighted eye that has a near point of 40 cm .Determine the maximum magnifying power of a compound microscope equipped with a 25 diopter lens as the objective and a 5 diopter lens as the eyepiece, given a separation of 30 cm bIn a compound microscope, the separation between the objective and the eyepiece is adjustable between 9.8 cm and 11.8 cm . Given that the focal lengths of the objective and the eye Full Optical Instruments list All Concepts Of Physics MCQ Edition [Volume 1] PYQs