CBSE Class 8 Science Chapter 13 Long Answer Type Questions
Question 1. Them Is n mistake in each of the following ray diagrams given ns figure (a), (b). and (c). Make the necessary correction (s).
Answer: The correct diagrams are as below
” Light Reflection And Refraction Class 8 “
Question 2. A man stands 10 m in front of a large plane mirror, so how far must he walk before he is 5 m away from his image?
Answer: As, per the given information, point 0 is initial position of the man and I is initial position of the image of the man can be show with the help of a figure.
Point O’ is final position of the man and I’ is final position of the image of the man. From the figure.
O’P + PI’ = 5m [0’P = PI’]
0’P + 0’P = 5m
0’P = 25m
Distance walked by the man = OP- O’P
= 10-2.5 = 7.5m
” Laws Of Reflection Class 8 “
Read And Learn More CBSE Class 8 Science Long Answer Questions
Question 3. Aditya visited a lake on two days. On the first day, the reflection of the surrounding mountains could be seen clearly in water of the lake. On the second day, he was not able to see the reflection of the mountains clearly. Give one possible reason for this phenomenon and explain your answer clearly.
Answer: The unclear image of the mountains on the second day is probably due to wind blowing across the lake causing it to lose its calmness. When the lake is calm, the surface of the lake is smooth and regular reflection occurs, allowing a clear image of the mountains to be formed. When the wind blows across the lake, the surface of the lake becomes rough and uneven causing a diffused reflection, lienee, the image formed of the mountains will be unclear and blurred.
Question 4. Figure shows tho word REST written In two ways In front of a mirror. Show how the word would appear In the mirror?
” Virtual Image Formation Class 8 “
Answer: According to reflection properties of plane mirror, it forms same size, laterally inverted images of the object infront of them.
” Image Formation By Plane Mirror “
Question 5. Boojho planned an activity to observe an object A through pipes as shown in figure, so that he could see objects which he could not directly see.
1. Mention how many mirrors should he use to see the objects?
Answer: Number of mirrors = 3
” Periscope Working Principle “
2. Indicate the positions of the mirrors in the figure.
Answer: Positions of the mirrors are as shown in figure
3. State what must be the angle w.r.t. the incident light at which he should place the mirrors?
Answer: Mirrors should be placed at 45° w.r.t. the incident light, so that ray can move forward.
” Diffused Reflection Class 8 “
4. Indicate the direction of rays in the figure of (2) Part.
Answer: Direction of rays is shown in figure.
5. If any of the mirrors is removed, will he be able to see the objects?
Answer: He will not be able to see the objects ifany of the mirrors is removed, since he will not get the rays after that removed mirror.
” Cbse Class 8 Science Long Answer Questions “
