What is long-sightedness? What type of lens is used to remedy this defect? [2+1]
WBBSE
Class X
Physical Science
Light – Reflection and Refraction
03 Mark
2022
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
1/12
Q.
What is meant by the principal axis of a concave lens?
A.
The principal axis of a concave lens is an imaginary straight line...
Q.
Determine the angle of deviation for the refraction of light rays from rarer to denser...
A.
The angle of deviation (δ) for light rays passing from a rarer...
Q.
If the refractive indices of a medium for red and blue colours of light are...
A.
μr < μb
Q.
Which type of mirror is used in the headlight of a motor car?
A.
A concave mirror is used in the headlight of a motor car.
Q.
Is it possible to form a virtual image of shorter length than the length of...
A.
Yes, it is possible to form a virtual image of a shorter...
Q.
Dentists use (a) convex mirror (b) convex lens (c) concave mirror (d) concave lens
A.
(c) Concave mirror Explanation: Dentists use concave mirrors because they produce a...
Q.
The wavelength of which of the following is greater than that of visible light?
A.
(b) Infrared ray Explanation: Infrared rays have a longer wavelength than visible...
Q.
If the radius of curvature of a concave mirror is 20 cm, then focal length...
A.
(c) 10 cm Explanation: The focal length (f) of a concave mirror...
Q.
Define dispersion of light. How would you identify monochromatic light and composite light with the...
A.
Dispersion of Light is the phenomenon where light splits into its constituent...
Q.
Write down the relationship between relative refractive index and absolute refractive index. On which factors...
A.
Relative refractive index of medium 2 with respect to medium 1: 1μ2...
Q.
Draw refracted rays for the incident rays which are parallel to the principal axis of...
A.
Ray Diagram for convex lens: OR Converging action of the convex lens...
Q.
A light is incident from air medium on another medium. If the refractive index of...
A.
Finding the wavelength: μ = 1.5 λmedium ​= 4000 Å λair =...