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  • Class 8 Science Study Material

An Educational platform for Preparation and Practice Class 8. Kidsfront provide unique pattern of learning Science with free online comprehensive study material in the form of QUESTION & ANSWER for each Chapter of Science for Class 8. This study material help Class 8, Science students in learning every aspect of Light . Students can understand Light concept easily and consolidate their learning by doing Online Practice Tests on Science,Light chapter repeatedly till they excel in Class 8, Light . Free ONLINE PRACTICE TESTS on Class 8, Light comprise of Hundreds of Questions on Light , prepared by the highly professionals team. Every repeat test of Light will have new set of questions and help students to prepare themselves for exams by doing unlimited Online Test exercise on Light . Attempt ONLINE TEST on Class 8,Science,Light in Academics section after completing this Light Question Answer Exercise.


Unique pattern

  • Topic wise:Light preparation in the form of QUESTION & ANSWER.
  • Evaluate preparation by doing ONLINE TEST of Class 8, Science,Light .
  • Review performance in PRACTICE TEST and do further learning on weak areas.
  • Attempt repeat ONLINE TESTS of Science Light till you excel.
  • Evaluate your progress by doing ONLINE MOCK TEST of Class 8, Science, All TOPICS.


Light
An pencil of length 10 cm is placed before a plane mirror. The length of the image of the pencil formed will be

a) 1 cm.
b) 5 cm.
c) 10 cm.
d) 20 cm.



Answer
Solution
Correct Answer Is : 10 cm.
Solution Is : The image formed by a plane mirror is of the same size as the object. Hence, the image of a pencil of length 10 cm will also have the same length.
At the images formed by a plane mirror, the light rays coming from the objects

a) Actually meet.
b) Appear to meet.
c) Get reflected.
d) Get transmitted.



Answer
Solution
Correct Answer Is : Appear to meet.
Solution Is : The image formation by a plane mirror is shown as follows: From the figure, it is clear that the light rays coming from the object appear to meet at the image formed.
The image formed by a plane mirror is

a) Erect.
b) Inverted.
c) Real.
d) Distorted.



Answer
Solution
Correct Answer Is : Erect.
Solution Is : When an object is placed upright in front of a plane mirror, the image formed is also upright. Therefore, we can conclude that the image formed by a plane mirror is erect.
A boy stands 50 cm away from a plane mirror. The image will be formed at

a) 25 cm away from the mirror.
b) 50 cm away from the mirror.
c) 100 cm away from the mirror.
d) 200 cm away from the mirror.



Answer
Solution
Correct Answer Is : 50 cm away from the mirror.
Solution Is : The image formed by a plane mirror is at the same distance from the mirror as the object. Therefore, if a boy stands 50 cm away from a plane mirror, his image will be formed at 50 cm away from the mirror.
A plane mirror is broken into five pieces. The total number of images of an object formed by the mirrors will be

a) One.
b) Three.
c) Five.
d) Ten.



Answer
Solution
Correct Answer Is : Five.
Solution Is : Each piece of mirror will act as an independent mirror. Therefore, each mirror will form an image of the same object. Hence, the total number of images of the object is five.
Three light rays incident on a plane mirror have angles of incidence i1, i2 and i3 where, (i1< i2 < i3). The angles of reflection are r1, r2 and r3. Then,

a) R1 = r2 = r3.
b) R1 > r2 > r3.
c) R1 < r2 < r3.
d) R1 > r2 < r3.



Answer
Solution
Correct Answer Is : R1 < r2 < r3.
Solution Is : According to the Laws of Reflection, angle of incidence is equal to the angle of reflection. Therefore, if i1< i2 < i3, then r1 < r2 < r3.
The still photographs of a flying bird are kept one upon the other in a proper sequence and the photographs are flipped over at a rate faster than 16 s. Then, the eye perceives the bird as

a) Still.
b) Moving.
c) A circular blurred object.
d) A circular clear object.



Answer
Solution
Correct Answer Is : Moving.
Solution Is : The impression of an image does not vanish immediately from the retina. It persists there for about 1/16th of a second. Therefore, if the still photographs of a flying bird are kept one upon the other and the photographs are flipped over at a rate faster than 16 s, then the eye perceives the bird as moving.
After coming out into bright sunshine from a dark room, we feel a glare in our eyes for sometime because the size of our pupil is

a) Smaller than the normal size.
b) Bigger than the normal size.
c) Zero.
d) Equal to the normal size.



Answer
Solution
Correct Answer Is : Bigger than the normal size.
Solution Is : When we are in a dark room, the size of our pupil is bigger than the normal size. This enables our eyes to collect more amount of light. When we come out into bright sunshine, the size of pupil cannot be reduced immediately. So, larger amount of light enters our eyes. This causes a glare in our eyes.
When the tube of a Kaleidoscope is rotated, the tumbling of the multi-coloured objects give

a) The repeated beautiful multi-coloured patterns.
b) The repeated beautiful single-coloured patterns.
c) The unrepeated beautiful multi-coloured patterns.
d) The unrepeated beautiful single-coloured patterns.



Answer
Solution
Correct Answer Is : The unrepeated beautiful multi-coloured patterns.
Solution Is : Kaleidoscope is a tube of mirrors containing coloured pieces of bangles. The setting of the mirrors at an angle 45? creates eight duplicate images of the objects, six at 60? and four at 90?. When the tube is rotated, the tumbling of the coloured objects give the unrepeated beautiful patterns.
A square of area 250 cm2 is placed before a plane mirror. The area of the image will be

a) 125 cm2.
b) 250 cm2.
c) 500 cm2.
d) 1000 cm2.



Answer
Solution
Correct Answer Is : 250 cm2.
Solution Is : Since the image formed by a plane mirror is of the same size as the object. Hence, the image of a square of area 250 cm2 will have the same area.