Which one among the following is correct for a person suffering from myopia?
- A.The person can see near objects clearly
- B.The person can see distant objects clearly
- C.The person cannot distinguish colours
- D.The person can neither see near objects nor distant objects clearly
Correct answer
Explanation
The correct answer is A, The person can see near objects clearly. Myopia is short-sightedness: near objects look sharp but distant ones look blurred.
In a myopic eye the eyeball is too long or the eye lens is too curved, so light from a distant object comes to a focus in front of the retina instead of on it. The far point of the eye moves closer than infinity. The defect is corrected with a concave (diverging) lens, which spreads the rays slightly so that the image forms on the retina.
B is wrong because clear distant vision with blurred near vision is hypermetropia (long-sightedness).
C is wrong because failing to tell colours apart is colour blindness, a defect of the cone cells.
D is wrong because blur at both distances describes presbyopia combined with other defects, often corrected with bifocal lenses.
Exam tip: myopia = near-sighted, image before retina, concave lens; hypermetropia = far-sighted, image behind retina, convex lens.
Practice Questions
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- A.1 pascal
- B.1 atmosphere
- C.1 bar
- D.1 poise
Show answer
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- B.respectively transverse and longitudinal in air
- C.both longitudinal in air
- D.both transverse in air
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- A.Charcoal
- B.Coke
- C.Fullerene
- D.Carbon black
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Read the full explanation →A planet has a mass M₁ and radius R₁. The value of acceleration due to gravity on its surface is g₁. There is another planet 2, whose mass and radius both are two times that of the first planet. Which one of the following is the acceleration due to gravity on the surface of planet 2?
- A.g₁
- B.2g₁
- C.g₁/2
- D.g₁/4
Show answer
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Read the full explanation →Which one of the following is the major constituent of biogas ?
- A.Carbon dioxide
- B.Nitrous oxide
- C.Methane
- D.Oxygen
Show answer
Methane makes up the largest share of biogas, usually about 55 to 75 per cent, and it is the gas that burns.
Read the full explanation →