Light Flashcards
Define refraction of light
The change in the direction of path of light when it passes from one transparent medium to another transparent medium is called refraction
State the laws of refraction
The incident ray the refracted Ray and the normal at the point of incidence all lie in the same plane the ratio of the sign of angle of incidence I to the sign of angle of R is constant for the pair given the media
What is a refractive index
The refractive index of second medium with respect to the first medium is defined as the ratio of the sign of angle of incidence in the first medium to the sign of angle of refraction in the second medium
Represent the refractive index of a medium 2 respect to medium 1
1U2
State the principle of reversibility
1u2 x 2u1 =1
State the factors that affect lateral displatement of light
The thickness of the medium the angle of incidence the refractive index
How does the angle of incidence affect the lateral displacement
More the angle of incident more the lateral displacement
How does wavelength affect lateral displacement
Since refractive index increases with the decrease in wavelength of light so lateral displacement increases with the decrease in wavelength of light
Violet light and red light which one has more lateral displacement
Violet light has more lateral displacement
How how is angle of deviation affected by angle of incidence
With the increase in angle of incident the angle of deviation starts to decrease till it reaches a certain angle of incidence where it starts to increase
When is the angle of deviation the least
Angle of deviation is the least when the angle of incidence is equals to the angle of emergence
How does Critical Angle effect the angle of incidence moving from a denture medium to rare medium
Is the angle of incidence is less than the critical angle then the incident grey gets refracted is the angle of incidence is equals to Critical Angle then the angle of incidence is parallel to the 90 degree of the normal is the angle of incidence is greater than the critical angle then total reflection takes place
Define real and Apparent depth
An object placed in a denture medium when viewed from a rare medium appears to be at a depth lesser than its real death this is because of refraction of light
The mathematical formula relating real depth and
A u m is equals to real depth by Apparent depth
Relationship between critical angle and the refractive index
gUa = sin c / sin 90⁰
Sin 90⁰ = 1
Therefore, gUa =sin c
Factors affecting the critical angle
Independence upon the colour of light it depends on the temperature
Define total internal reflection
When light Ray Travelling in a denser medium is incident at the surface of the rear or medium At an angle of incidence greater than the critical angle For the pair of media the ray is totally reflected back into the denser medium this phenomena is called the total internal deflection
What are the essential conditions for total internal
The light must travel from denser to rare medium the angle of incidence must be greater than the critical angle for the pair of media
What is critical angle
Critical angle is the angle of incidence in the denser medium corresponding to which the angle of refraction being 90 degree in the rare medium
State the formula for linear magnification
M is equals to V by U
State the lens formula
1/v - 1/u = 1/f
State the magnifying power formula and its
Magnifying power = 1 +D/f
State the formula for power of lens and the units its
Power is equals to 1 by focal length in metre power is measured in diopter
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