Q2 of 9 Page 115

Draw a figure describing the following. The reflecting surfaces of two mirrors make an angle of 900 with each other. If a ray incident of one mirror has an angle of incidence of 300 , draw the ray reflected from the second mirror. What will be its angle of reflection?

Figure below shows the required figure.



In the above figure in Triangle AOB we have


∠ A = 300 (Angle of reflection (∠ A) = Angle of incidence = 300


∠ O = 900 (Normal to mirror are perpendicular to each other)


Since AOB is triangle


∴ ∠ A + ∠ O + ∠ B = 1800


⇒ 300 + 900 + ∠ B = 1800


⇒ ∠ B = 1800 - 300 - 900


⇒ ∠ B = 1800 – 1200 = 600


⇒ Angle of incidence for second ray = 600


By Laws of Reflection of Light


Angle of Incidence = Angle of Reflection


⇒ Angle of Reflection = 600


More from this chapter

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1

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i. The perpendicular to the mirror at the point of incidence is called............


ii. The reflection of light from a wooden surface is.............. reflection.


iii. The working of Kaleidoscope is based on the properties of ..............

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 4

Explain the difference between the regular and irregular reflection of light.

 5

Draw a figure showing the following.

a. Incident Ray


b. Normal


c. Angle of incidence


d. Angle of reflection


e. Point of incidence


f. Reflected ray