A myopic person prefers to remove his spectacles while reading a book. Why ?
Text Solution
Verified by Experts
A myopic person has to use spectacles with concave lens. He may have normal near point `(~~ 25 cm)`. To read with specs, he has to hold the book at a distance greater than `25 cm`. As angular size of object at a distance `gt 25 cm` is less than the angular size of object at `25 cm`, therefore, the person perfers to remove his spectacles while reading.
Topper's Solved these Questions
OPTICS
PRADEEP|Exercise Very short answer question|5 Videos
OPTICS
PRADEEP|Exercise very short answer questions|1 Videos
A short sighted person can see objects most distinctly at a distance of 16 cm . If he wears spectacles at a distance of 1 cm from the eye, what focal length should he have so as to enable him to see distinctly at a distance of 26 cm ? ( c) The person above prefers to remove his spectacles while reading a book. Explain why ? (NCERT Solved Example)
(a) The far point of a myopic person is 80 cm . In front of the eye. What is the power of the lens required to enable him to see very distant objects clearly ? (b) In what way does the corrective lens help the person above ? Does the lens magnify very distant objects ? Explain carefully. ( c) The person above prefers to remove his spectacles while reading a book. Explain why ?
(a) The near point of a hypermetropic person is at 75 cm from the eye. What is the power of the lens required to enable him to read clearly a book held at 25 cm from the eye ? (b) In what way does the corrective lens help the person above ? Does the lens magnify objects held near the eye ? ( c) The person above prefers to remove his spectacles while looking at the sky. Explain why ?
A cricket player lowers his hands while catching a ball . Why ?
Long -sighted people who have lost their spectacles can still read a book by looking through a small (3-4mm) hole in a sheet of paper
