Plane Mirror

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Ques) Two plane mirrors each 1.6 m long, are facing each other. The distance b/w the mirrors is 20 cm. A light incident on one end of one of the mirrors at an angle of incidence of 30 Â°. How many times is the ray reflected before it reaches the other end ???

#Physics #Optics

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6 Answers

4

UTTARA ·2009-10-31 07:29:31

If the 2 mirrors r parallel then âˆž images r formed due to multiple reflections

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1

varun.tinkle ·2009-10-31 08:28:23

simple sum form geometry......
since the angle of incidence is 30 so angle of reflection is also 30 therefore applying geometry tan30=3^-0.5
so the perpendicualr distance we can know the distance travelled by the ray before it strikes again
therefore 1.6=n1.5/root 3

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varun.tinkle ·2009-11-03 07:18:11

i think now using trigo and tan 30 u can get the answer

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24

eureka123 ·2009-11-03 08:49:49

@ uttara...he has asked not no. of images..he asked no. of times ray is reflected..which will be finite

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UTTARA ·2009-11-03 08:54:53

@eureka : Ya u r right

I mistook the Qs

I guess varun.tinkle is right!!!

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Tush Watts ·2009-11-04 04:35:38

Thanx a lot varun

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Your Answer

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