QQuestion
What is long-sightedness? What type of lens is used to remedy this defect? [2+1]
✓Answer
Long-sightedness, also known as hypermetropia, is a vision defect in which a person can see distant objects clearly but has difficulty focusing on nearby objects. This happens because the image of close objects is formed behind the retina instead of directly on it, often due to a shorter-than-normal eyeball or a less curved cornea.
To correct long-sightedness, a convex lens is used.
Related Questions
More WBBSE Easy level questions
What is meant by the principal axis of a concave lens?
Determine the angle of deviation for the refraction of light rays from rarer to denser medium. [2] (angle of incidence = i, angle of refraction = r) OR Why do the green leaves of trees appear 'green' in sunlight? [2]
If the refractive indices of a medium for red and blue colours of light are μr and μb respectively, which one is greater in magnitude?
Which type of mirror is used in the headlight of a motor car?
Is it possible to form a virtual image of shorter length than the length of the object by any mirror?
Dentists use (a) convex mirror (b) convex lens (c) concave mirror (d) concave lens
The wavelength of which of the following is greater than that of visible light? (a) x-ray (b) infrared ray (c) γ - ray (d) ultraviolet ray
If the radius of curvature of a concave mirror is 20 cm, then focal length of the mirror will be (a) 20 cm (b) 15 cm (c) 10 cm (d) 40 cm
Define dispersion of light. How would you identify monochromatic light and composite light with the help of a prism? [1 + 2]
Write down the relationship between relative refractive index and absolute refractive index. On which factors does the relative refractive index of a medium depend? [1 + 2] OR Show that if a monochromatic light ray passes symmetrically through an equilateral prism then the angle of deviation of that ray will be minimum
Draw refracted rays for the incident rays which are parallel to the principal axis of a convex lens. Mark focus (F). [3] OR Explain the converging action of a convex lens. [3]
A light is incident from air medium on another medium. If the refractive index of this medium is 1.5 and the wavelength of light in this medium is 4000 Å what is the wavelength of light in the air medium ? What is the velocity of the light in this medium? [3] OR As a result of refraction of light through an equilateral prism the angle of deviation becomes 40°. If the path of the ray through the prism is parallel to the base of the prism, determine the angle of incidence at the first surface of prism. [3]