Reflection Of Light
Class 8th Science (old) MHB Solution
- How many times is an image in a plane mirror bigger or smaller than the object? Answer the…
- Where is the image formed in a plane mirror located? Answer the following questions.…
- Explain the difference between regular and irregular reflection. Answer the following…
- How many images are obtained in two parallel mirrors? Answer the following questions.…
- Why are the two mirrors in a periscope placed parallel to each other? Answer the following…
- Give reasons. (a) Letters appear laterally inverted in a plane mirror. (b) Numerous images…
- Match the following.
- Fill in the blanks. (a) The incident ray, the normal and the reflected ray are all in the…
Exercises
Question 1.Answer the following questions.
How many times is an image in a plane mirror bigger or smaller than the object?
Answer:
The image in a plane mirror is upright and it is neither smaller nor bigger but is of the same size as that of the object.
Question 2.
Answer the following questions.
Where is the image formed in a plane mirror located?
Answer:
The image is formed at the back of the mirror and at the same distance from it as the object.
Question 3.
Answer the following questions.
Explain the difference between regular and irregular reflection.
Answer:
Question 4.
Answer the following questions.
How many images are obtained in two parallel mirrors?
Answer:
Infinite number of images are obtained when two mirrors are placed parallel to each other.
Question 5.
Answer the following questions.
Why are the two mirrors in a periscope placed parallel to each other?
Answer:
In a periscope, two mirrors are placed at an angle of 45 degrees and at the maximum distance. Due to maximum distance between the mirrors, multiple images do not form and light from the object strike the first mirror and its image is formed. This image of first mirror becomes an object for the second mirror and as they are parallel, light from the first mirror gets incident on the second mirror at right angle and the same image is thus formed. Therefore, the mirrors are kept parallel to each other.
Question 6.
Give reasons.
(a) Letters appear laterally inverted in a plane mirror.
(b) Numerous images are seen in the 'Palace of Mirrors'.
(c) The image formed in water is of the same size as the object
Answer:
(a) Due to lateral inversion that is the right and the left sides get interchanged between image and the object, letters appear laterally inverted in a plane mirror.
(b) ‘Palace of Mirrors’ have numerous mirrors placed at different angles. When a person enters the palace, light from him gets reflected by all the mirrors at different angles and due to multiple reflection, multiple images are formed.
(c) Image formed in water is of the same size as water acts as a plane mirror and light rays get reflected from it thus producing image of same size.
Question 7.
Match the following.
Answer:
Question 8.
Fill in the blanks.
(a) The incident ray, the normal and the reflected ray are all in the same……………
(b) Reflection from a rough surface is called ……………reflection.
(c) In a periscope, we sec …………… reflection of an object.
(d) In a plane mirror, the image is…………… inverted.
Answer:
(a) The incident ray, the normal and the reflected ray are all in the same…plane…………
(b) Reflection from a rough surface is called …irregular…………reflection.
(c) In a periscope, we see …second………… reflection of an object.
(d) In a plane mirror, the image is…laterally………… inverted.
Activities
Question 1.Place two mirrors parallel to each other and count the number of images formed in them.
Answer:
Place two mirrors of same size parallel to each other. Now, take a pencil and hang it in between them so that it is at equal distance from the two mirrors. Now try to count the number of images thus formed. You will find that there are infinite number of images formed. Well it will be wrong to say infinite number of images as image is formed only once but it gets reflected infinite times.