Deviation, Dispersion and Spectrum Flashcards
What does the first deviation of a ray of light in a prism depend on?
- the angle of incidence
2. the refractive index of glass w.r.t air
What does the second deviation of a ray of light in a prism depend on?
- the angle of incidence at the second surface
2. the refractive index of air w.r.t glass
What does the angle of incidence at the second surface inside a prism depend on?
The angle of the prism A
What does the total angle of deviation depend on?
- the angle of incidence at the first surface
- the angle of the prism (A)
- the refractive index of the material of the prism
Why does the total angle of deviation depend on the color or wavelength of light used?
Because refractive index depends on the color and wavelength of light used, and angle of deviation depends on refractive index
What happens to the emergent beam if the light entering the prism is a mixture of several colors?
The emergent beam too has different colors arranged in a definite order
Why does the deviation caused by a prism increase with the decrease in the wavelength of light?
Since the refractive index of glass (material of the prism) increases with the decrease in wavelength of light
Which color is deviated the most?
Violet color
Which color is deviated the least?
Red color
Why is violet color deviated most and red the least?
In glass, the speed of violet light is the least and that of red light is the most
What produces the sensation of different colors on the retina of our eye?
The light of different wavelengths
Name the characteristic of color, irrespective of its origin
Wavelength
What odes it mean for wavelength to be the characteristic of color, irrespective of its origin?
Light of the same color obtained from different sources will have the same wavelength
Name the subjective property of light related to its wavelength
Color
Give the wavelength range of violet color
4000 A to 4460 A
Give the wavelength range of red color
6200 A to 8000 A
What does the letter A denote?
The unit Angstrom
What is the value of 1 Angstrom in m?
1 A = 10^-10 m
What is the value of 1 Angstrom in cm?
10^-8 cm
What is the value of 1 nm in Angstrom?
1 nm = 10 A
What is the frequency of red color?
3.75* 10^14 Hz
What is the frequency of violet color?
7.5 * 10^14 Hz
What is the trend in wavelength and frequency from the violet end to the red end of the spectrum?
The wavelength increases, and the frequency decreases
What is the term for white light being a mixture of large number of wavelengths?
It is polychromatic in nature
How many prominent colors does white light consist of?
Seven prominent colors
Define dispersion
The phenomenon of splitting of white light by a prism into its constituent colors
Define spectrum
On passing white light through a prism, the band of colors seen on a screen is called spectrum
What is the cause of dispersion of white light?
The lights of different wavelengths travel with different speeds in a medium. When white light enters the first surface of a prism, light of different colors due to their different speed in glass, get deviated through different angles towards the base of the prism
At which surface does dispersion take place?
At the first surface of the prism
At which surface does deviation of light rays occur?
At both the surfaces of the prism
