Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
The ratio of speed of light in vacuum to the speed of light in a medium is called the _______ of the medium.
Frequency
Wavelength
Refractive index
Amplitude
None of the above
Refractive index
The refractive index is a dimensionless physical quantity that measures how much the path of light is bent or slowed when entering a material. It is defined as the ratio of the speed of light in a vacuum (c) to its speed in a given medium (v).
The refractive index is a dimensionless physical quantity that measures how much the path of light is bent or slowed when entering a material. It is defined as the ratio of the speed of light in a vacuum (c) to its speed in a given medium (v).
Think of light as a person running; the vacuum is like a clear running track, while the medium (like water or glass) is like running through waist-deep waterтАФthe resistance makes the runner slower.
n = c/v : 'n'ever 'c'atch 'v'elocity (n equals c over v).
n=vcтАЛ тАФ where n is the refractive index, c is the speed of light in vacuum (approx3├Ч108┬аm/s), and v is the speed of light in the medium.
When light travels from vacuum into a denser medium, it interacts with the atoms and molecules of the medium, causing the effective speed to decrease. According to the principle of Fermat, light takes the path that minimizes time, leading to refraction at the interface of media with different refractive indices. The degree of this optical density is expressed by the refractive index n=vcтАЛ.
Refractive index is a unitless ratio.
The refractive index of a vacuum is exactly 1.
For any material medium, the refractive index is always greater than 1 because v<c.
A higher refractive index indicates a higher optical density.
Used to identify substances based on light bending.
Essential for designing lenses, spectacles, and optical fiber communication.
Varies with the wavelength of light (a phenomenon known as dispersion).
Determination of concentration of solutions using a refractometer.
Design of corrective lenses for vision.
Speed of light in vacuum is cтЙИ299,792,458┬аm/s.
Option A (Frequency) is determined by the source and does not change when light enters a new medium.
Option B (Wavelength) changes proportionally with the speed (v=f╬╗), but is not the definition of the ratio given.
Option D (Amplitude) relates to the intensity or brightness of light, not the ratio of speeds.
C is correct тАФ The refractive index is defined as the ratio of the speed of light in a vacuum to the speed of light in a medium.
Remember that while the speed and wavelength of light change when entering a different medium, the frequency remains constant.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants