The question asks to identify the second law of reflection, given that the first law states the angle of incidence equals the angle of reflection. We need to recall the fundamental laws governing the reflection of light from a surface.
D) The incident ray, reflected ray, and normal all lie in the same plane
This statement accurately describes the second law of reflection. It ensures that the reflection occurs in a two-dimensional plane, simplifying the analysis of light paths.
The problem asks for the angle of reflection when a ray of light strikes a plane mirror. We are given the angle the incident ray makes with the mirror surface. To solve this, we need to understand the Law of Reflection and the definitions of the angle of incidence and the angle of reflection.
C) The angle of reflection is 60°, as calculated from the Law of Reflection after determining the angle of incidence.
The question asks about the characteristics of an image formed by a plane mirror. We need to recall the properties of images formed by plane mirrors, which are fundamental concepts in optics.
Based on these properties, we can evaluate the given options.
Correct Option: D) Virtual, erect, and laterally inverted
To determine the minimum size of a plane mirror required for a person to see their complete image, we need to apply the laws of reflection. Specifically, we will use the principle that the angle of incidence equals the angle of reflection and consider the light rays originating from the top of the person's head and their feet.
Let the height of the person be \(H\). Let the person's eyes be at a height \(E\) from the ground, the top of their head at height \(H\), and their feet at height \(0\).
To see the top of their head, a light ray from the top of the head must strike the mirror and reflect into the person's eyes. Let the point where this ray strikes the mirror be \(M_1\). Due to the law of reflection and similar triangles, the mirror needs to extend at least halfway between the top of the head and the eyes. So, the upper edge of the mirror should be at a height of \(\frac{H+E}{2}\) from the ground.
To see their feet, a light ray from the feet must strike the mirror and reflect into the person's eyes. Let the point where this ray strikes the mirror be \(M_2\). Similarly, the mirror needs to extend at least halfway between the feet and the eyes. So, the lower edge of the mirror should be at a height of \[\frac{0+E}{2} = \frac{E}{2}\] from the ground.
The minimum vertical length of the mirror required is the difference between the height of its upper edge and its lower edge.
\[ \text{Minimum mirror length} = \text{Height of upper edge} - \text{Height of lower edge} \]\[ \text{Minimum mirror length} = \frac{H+E}{2} - \frac{E}{2} \]\[ \text{Minimum mirror length} = \frac{H+E-E}{2} \]\[ \text{Minimum mirror length} = \frac{H}{2} \]This result shows that the minimum height of the mirror required is half the height of the person, regardless of the person's distance from the mirror or the position of their eyes (as long as they are between the top of the head and the feet).
C) H/2 is the correct answer. The minimum size of a plane mirror required for a person of height H to see their complete image is H/2.
The problem asks for the angle of reflection when a ray of light is incident normally on a plane mirror. To solve this, we need to recall the laws of reflection, specifically how the angles of incidence and reflection are defined and related.
D) 0° is the correct answer because when a ray is incident normally, it coincides with the normal, making the angle of incidence \(0^\circ\). By the law of reflection, the angle of reflection is also \(0^\circ\).
To find the number of images formed by two plane mirrors inclined at an angle, we use a specific formula. The formula depends on whether the ratio \(360^\circ / \theta\) is an even or an odd integer.
D) 5. When two plane mirrors are inclined at an angle of \(60^\circ\), the ratio \(360^\circ / 60^\circ = 6\), which is an even number. Therefore, the number of images formed is \(6 - 1 = 5\).