Question

1)what would be the angle of reflection if an incident ray make an angle of 70° with the normal of the plane mirror
a.30°
b.50°
c.70°
d.100°
2) which of the following devices based on multiple reflection?
a. prism
b. Kelliedoscope
c. Periscope
d. both (b) and (C)
3) when two plane mirror are kept at 60 degree to each other we get________.
a. 3 images
b. 4 images
c. 5 images
d. 6 images
4) what is the minimum distance which a normal human eye can see distinctly?
a. 25 CM
b. 25m
c. 2.5 m
d. 2.5 CM
9) for twoparallel mirrors facing each other the number of images formed are:
a. 20
b. 10
c. 6
d. infinite
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Answer 1

Answer:

1) c. 70°

2) d. both (b) and (C)

3) c. 5 images

4) a. 25 CM

9) d. infinite

Explanation:

1) According to the law of reflection, Angle of incidence is always equal to angle of reflection in a plane mirror.

2) In a Prism a white light refracts into 7 different lights VIBGYOR- Violet, Indigo, Blue, Green, yellow, Orange and Red.

3) You can get it by the formula n= 360/θ, where θ is the angle made by the mirrors. n= 360/60= 6. As 6 is an even number, we have subtract one as we have assumed the mirror to be symmetrical. Therefore, Number of image is 6-1= 5.

4) A normal human eye can view a minimum distant of upto 25cm

9) 2 parallel mirrors facing each other will form infinite image.

Hope you find it helpful...