What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incident ray?
∠i + ∠r = 90◦
But, by the first law of reflection;
∠i = ∠r
∠i + ∠r = 90◦
∠i + ∠i = 90◦
2∠i = 90◦
∠i = 90◦ = 45◦ 2
In the following Table some substances are given in Column I. In Column II some uses are given. Match the items in column I with those in Column II.
Column I | Column II |
---|---|
(i) Gold (ii) Iron (iii) Aluminium (iv) Carbon (v) Copper (vi) Mercury |
(a) Thermometers (b) Electric Wire (c) Wrapping food (d) Jewellery (e) Machinary (d) Fuel |
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Welcome to the NCERT Solutions for Class 8 Science - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 13: What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incide....
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