What is the angle of incidence of array if the reflected ray is at an angle of 19 degree to the incident ray?

Last updated at June 11, 2021 by Teachoo

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According to the question, reflected angle is at an angle of 90° to incident ray ∴ ∠AOB = 90° ∠i + ∠r = 90° …(1) According to the law of reflection, Angle of incidence = Angle of reflection ∠i = ∠r Putting ∠i = ∠r in equation (1) ∠i + ∠i = 90° 2 ∠i = 90° ∠i = 90/2 ∠i = 45° ∴ Angle of incidence = 45°

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Answer:

Solution:

angle\ i+angle\ r=90^{\circ}

But according to laws of reflection,

angle i = angle r

So, replacing angle r by angle I,

anglei+anglei=90^{\circ}

2(angle\ i)=90^{\circ}

(anglei)=\frac{90^{\circ}}{2}=45^{\circ}

Video transcript

hello everyone welcomes to yet another lido homework session in today's class, we are going to be Solving a science problem so let's begin with the question the question here is what is the angle of incidence of a ray if the reflected ray is at an angle of 19 degrees to the incident ray so the question here we have to find is the Angel of incident the angle of the incident ray so let's begin as it's already been given in the Question: angle of the reflected ray is at an angle of 90 degree so let's start with our solution. the answer so Here I Am considering the angle of instant as I so the angle of incidence angle of incidence as I and Angel of an angle of reflected rays as the angle of reflection ray as r so the angle of the incident is I and anchor off reflected is r now we know that the angle of i plus the angle of r is 90 degree okay so according to the law of reflection according to the loss of Reflection what is according to loss of reflection yes the incident ray is always equal to Reflective ray so since incident ray is always reflected to is always equal to a reflected ray we can substitute this in our I am denoting this as my equation 1 in my Equation 1. so what I am going to do is instead of r I am going to replace r with i so instead of r I am going to replace it with I Am equal to 90 degree now where from where do we get it from equation two so from equation two we got that Since it is equal to r I have replaced my r with i no angle i plus angle i is 2 angles i am equal to 90 degree Now the angle i am equal to I Am taking the 2 to the denominator 90 by 2 Also, how much is 90 divided by 2 yes it is 45 so angle is 45 degree so i have found out that my incident ray is 45 degrees since the incident ray is 45 degree my reflected ray will also be 45 degrees so I can write the angle I equal to angler equal to 45 So, friends, I hope you have understood. the solution if you have any doubts or queries, please comment below and if you like this video give it a big thumbs up. and for further such videos, please subscribe to this channel till then thank you all

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Answer :

If the reflected ray is at the angle of 90 degrees to the incident ray, then the angle of incidence is 45 degrees. According to the law of reflection, the angle of incidence is equal to the angle of reflection. Therefore, the angle of incidence and the angle of reflection both are equal to

90/2 = 45 degrees.

What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incident ray?

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