The question asks which law of physics explains the rectilinear propagation of light. Rectilinear propagation means that light travels in straight lines in a uniform medium. We need to identify the fundamental principle that describes this behavior.
C) Newton's first law of motion. Although primarily formulated for objects with mass, the underlying principle of inertia – that something in motion continues in a straight line unless acted upon by an external influence – is the most analogous concept among the given options to explain why light propagates rectilinearly in a uniform medium. Light, in the absence of interactions (like refraction or reflection) or gravitational fields, maintains its straight path, much like an object maintains its state of motion according to Newton's first law.
The question asks about the behavior of light when it passes through a uniform medium. Understanding the fundamental properties of light propagation is key to answering this question.
Therefore, when light passes through a uniform medium, it continues to travel in a straight line.
C) It travels in a straight line. This is a fundamental principle of light propagation in a uniform, homogeneous medium.
The question asks about the first person to propose the theory of rectilinear propagation of light. This is a historical question related to the development of optics and physics. We need to recall the contributions of the scientists listed in the options to identify the correct answer.
A) Isaac Newton — Isaac Newton is widely credited with formalizing and popularizing the idea of light traveling in straight lines through his corpuscular theory. While earlier scientists might have observed this phenomenon, Newton's comprehensive work in "Opticks" established it as a cornerstone of his understanding of light.
The question asks about the meaning of "rectilinear propagation of light." This is a fundamental concept in optics, referring to how light generally travels. We need to identify the option that correctly describes this phenomenon.
A) Light traveling in a straight line — This option accurately defines "rectilinear propagation of light." In a homogeneous medium, light travels in straight lines. This is why we can draw ray diagrams using straight lines to represent the path of light.
The question asks to identify the color of light with the shortest wavelength. This relates to the electromagnetic spectrum, specifically the visible light portion, which is often remembered by the acronym VIBGYOR (Violet, Indigo, Blue, Green, Yellow, Orange, Red).
The relationship between the speed of light (\(c\)), frequency (\(\nu\)), and wavelength (\(\lambda\)) is given by the formula:
\[ c = \nu \lambda \]Since the speed of light in a vacuum (\(c\)) is constant, a shorter wavelength corresponds to a higher frequency, and a longer wavelength corresponds to a lower frequency.
D) Violet — Violet light is at one end of the visible spectrum, possessing the shortest wavelength and highest frequency among visible colors.
The speed of light changes when it passes from one medium to another. This phenomenon is governed by the refractive index of the media. We will analyze the relationship between the speed of light and the refractive index to determine how the speed changes when light enters a denser medium.
B) Decreases — When light enters a denser medium from a rarer medium, its speed decreases due to the higher refractive index of the denser medium.