Question

There is a mistake in each of the following ray diagrams given as, figure a, b and c. Make the correction (s)

Answer 1

Hint: The given question is related to the topic named reflection of light. The phenomenon of reflection of light is governed by the law of reflection which states that, when light is reflected from a surface the angle of incidence is always equal to the angle of reflection, where both angles are measured from the path of the light to the normal to the surface at the point at which light strikes the surface.

Complete step by step solution:
Figure (a): The figure given below is the first of the three given figures; the corrected figure is shown along with it. In this case, the direction of the incident ray has been shown in an incorrect manner. The incident ray should be directed towards the surface where as it is shown in the opposite direction.

Figure (b): The figure given below is the second of the three given figures; the corrected figure is shown along with it. In this case, the law of reflection has been violated as the angle of incidence is not equal to the angle of reflection. In order to correct this ray diagram the reflected ray must be inclined to the normal at an angle similar to that of the incident ray.

Figure (c): The figure given below is the last of the three given figures; the corrected figure is shown along with it. In this case, the side with which the angle of incidence and angle of reflection has been measured is not normal to the surface on which the light ray has struck. Hence, the entire ray diagram has been drawn incorrectly even if it follows the law of reflection.


Note: While drawing ray diagrams following things should be remembered.
Make sure that the ray diagram follows the law of reflection. I.e Angle of reflection (r) should be equal to angle of incidence (i) i.e $i=r$. Make sure that the direction of incident and reflected rays are shown properly. Make sure that the side with which the angles are measured is perpendicular to the surface.