science....class 8.....cahpter-10.....Refraction and Dispersion of light
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hi bro iam also 8class but we have light lesson
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Living Science for Class 8 Science Chapter 17 - Refraction And Dispersion Of Light
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Textbook Solutions Class 8 Science Refraction And Dispersion Of Light
Living Science Solutions for Class 8 Science Chapter 17 Refraction And Dispersion Of Light are provided here with simple step-by-step explanations. These solutions for Refraction And Dispersion Of Light are extremely popular among Class 8 students for Science Refraction And Dispersion Of Light Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Living Science Book of Class 8 Science Chapter 17 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Living Science Solutions. All Living Science Solutions for class Class 8 Science are prepared by experts and are 100% accurate.
Page No 225:
Question 1:
If medium A is optically denser than medium B, then the speed of light is
(a) the same in both mediums.
(b) higher in medium A than in medium B.
(c) higher in medium B than in medium A.
(d) higher in medium A or B depending on which medium is thicker.
ANSWER:
(c) higher in medium B than in medium A
The speed of light decreases in a denser medium.
Page No 225:
Question 2:
When light travels from an optically denser medium to a rarer medium.
(a) it bends away from the normal.
(b) it bends towards the normal.
(c) it is undeviated.
(d) it is laterally displaced.
ANSWER:
(a) it bends away from the normal
When light travels from an optically denser to a rarer medium, it bends away from the normal.
Page No 225:
Question 3:
The splitting of white light into its constituent colours is called
(a) refraction.
(b) dispersion.
(c) deviation.
(d) displacement.
ANSWER:
(b) dispersion
The splitting of white light into its constituent colours is called dispersion.
Page No 225:
Question 4:
At what position of the object does a convex lens act as a magnifying glass?
(a) between F and 2F
(b) between F and O
(c) beyond F
(d) beyond 2F
ANSWER:
(b) between F and O
In this case, the image formed is virtual, erect and bigger than the object.
Page No 225:
Question 5:
Which of the following is true for a person suffering from myopia?
(a) can see far-off objects clearly but near objects appear blurred
(b) can be corrected using a convex lens
(c) far point is at finite distance and not at infinity
(d) near point is beyond 25 cm
ANSWER:
(c) far point is at finite distance and not at infinity
In myopia or shortsightedness, the far point is not at infinity but at some finite distance.
Page No 225:
Question 6:
If a person is suffering from hypermetropia, which object is he/she most likely to see blurred?
(a) object 25 cm away
(b) object 10 m away
(c) object 100 m away
(d) object at infinity
ANSWER:
(a) object 25 cm away
In hypermetropia or longsightedness, a person is unable to see nearby objects clearly. A distance of 10 cm cannot be the answer, as at this distance even the vision of a person with normal eyes will also get blurred. Therefore, the object placed at a distance of 25 cm from the eye will look blurry to a person suffering from hypermetropia.
Page No 226:
Question 7:
Which one of these controls the amount of light entering the eye?
(a) pupil
(b) iris
(c) cornea
(d) ciliary muscles
ANSWER:
(b) iris
Iris controls the amount of light entering our eyes.
Page No 226:
Question 8:
Myopia is corrected by using spectacles with
(a) convex lenses.
(b) concave lenses.
(c) glass slabs.
(d) prisms.
ANSWER:
(b) concave lenses
Concave lenses diverge the parallel rays from a distant object in such a way that it starts appearing closer to the defective eyes.
Page No 226:
Question 9:
When white light passes through a prism, it is
(a) deviated and dispersed.
(b) deviated but not dispersed.
(c) laterally displaced and not dispersed.
(d) reflected.
ANSWER:
(a) deviated and dispersed
When white light passes through a prism, it gets deviated and dispersed.
Page No 226:
Question 10:
How many dots does the Braille system use?
(a) 5
(b) 6
(c) 10
(d) 11
ANSWER:
(b) 6
Braille system uses 6-dot cell.
Page No 226:
Question 1:
Refractive index can be defined for both transparent and opaque objects. True or false?
ANSWER:
False.
Since, opaque objects don't allow light to pass through them, they will also have no refractive index.