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Subject :NSO    Class : Class 7

In the given figure, two mirrors P and Q are situated at an angle of 60°with each other and a ray of light is incident on mirror P at an angle of 55°. What is the value of angle A if the ray again reflected by the mirror Q?


A 35°
B 55°
C 50°
D 70°


Ans 1:

Class : Class 7
Here the properties of lines and angles will be applied.Then the laws of reflection

Ans 2:

Class : Class 7
The correct is C

Ans 3:

Class : Class 9
I actually don't get the logic behind it

Ans 4:

Class : Class 9
I am not able to understand it

Ans 5:

Class : Class 7
Answer is (a). This is observed due to this reasonThere's a line which is making an angle 55° and is a linear pair. Hence the angle of line (mirror) p is 180°. But 55° is not the angle of incidence. To get the sum of angle of incidence and reflection, we multiply 55° by 2 and get 70°. Since angle of incidence =angle of reflection, 70°÷2=35°. The angle of incident ray and the reflected ray of P and Q are same thus the sum of the angle of incidence and angle of reflection would be the same (70°). We know, angle of incidence=angle of reflection, hence 70°÷2=35°. Or A=35°

Ans 6: (Master Answer)

Class : Class 1
The correct answer is C.

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