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A person has near point at 100 cm. What ...

A person has near point at 100 cm. What power of lens is needed to read at 20 cm if he/she uses (a) contact lens, (b) spectacles having glasses 2.0 cm separated from the eyes?

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C, D
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HC VERMA-OPTICAL INSTRUMENTS-Exercises
  1. A simple microscope is rated 5 X for a normal relaxed eye. What Nvill ...

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  2. Find the maximum magnifying power of a compound microscope having a 25...

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  3. The separation between the objective and the eyepiece of a compound mi...

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  4. An eye can distinguish between two points of an object if they are sep...

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  5. A compound microscope has a magnifying power of 100 when the image is ...

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  6. A compound microscope consists of an objective of focal length 1 cm an...

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  7. An optical instrument used for angular magnification has a 25 D object...

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  8. An astronomical telescope is to be designed to have a magnifying power...

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  9. The eyepiece of an astronomical telescope has a focal length of 10 cm....

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  10. A Galilean telescope is 27 cm long when focussed to form an image at i...

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  11. A farsighted person cannot see objects placed closer to 50 cm. Find th...

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  12. A nearsighted person cannot clearly see beyond 200 cm. Find the power ...

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  13. A person wears glasses of power - 2.5 D. Is the person short sighted o...

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  14. A professor reads a greeting card received on his 50th birthday with +...

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  15. A normal eye has retina 2 cm behind the eye-lens. What is the power of...

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  16. The near point and the far point of a child are at 10 cm and 100 cm. I...

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  17. A nearsighted person cannot see beyond 25 cm. Assuming that the separa...

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  18. A person has near point at 100 cm. What power of lens is needed to rea...

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  19. A lady uses + 1.5 D glasses to have normal vision from 25 cm onwards. ...

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  20. A lady cannot see objects closer than 40cm from the left eye and close...

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