refraction

what is refraction

refraction is the change in speed of a wave in a new medium

speed of light in a vacuum?

3 × 10^8 ms-1

what is the normal

the normal is an imaginary line that is drawn at 90 degrees to a surface It serves as a reference line to measure the angle of incidence and the angle of refraction

what is angle of incidence

angle of incidence is the light entering from a medium to another

what is angle of refraction

angle of refraction is the refracted ray and this light bends as it hits a new medium as the light slows down when the new medium has a different refractive index

what is refractive index

refractive index is how much light slows down in a material

explain what happens when light goes from a less dense medium to a more dense and what happens when it goes from more dense to less dense

when light goes from a less dense to a more dense medium it bends towards the normal slowing down however when going from a more dense to less dense for example light going from water into air the refracted ray will speed up and bend away from the normal

why does the refracted bend towards the normal when light goes from air to water but bends away from the normal when going from water to air

the reason for this is because when light goes from a less dense to more dense medium it slows down making it bend towards the normal however when the opposite happens the light speeds up and bends away from the normal

whats the formula for refractive index

n=c/v c=speed of light and v= speed of light in that material

what is the critical angle

the critical angle is when the angle of incidence is in the denser medium and the angle is big enough that the refracted ray is bending away from the normal at 90 degrees to the boundary to the point where it becomes a straight line and if the angle of incidence becomes even larger the refracted ray goes below the boundary and reflects internally this is called total internal reflection in short the criticle angle is when the refracted ray is at 90 degrees to the boundary

what is Snells law

snells law tells you how much light bends when entering a new medium

what is the formula for Snells law

n₁sin(θ₁) = n₂sin(θ₂)

n1 means refractive index of first medium

sin(θ₁) means angle of incidence

n2 means refractive index of second medium

sin(θ₂) means angle of refraction

light travels from water n=1.33 into glass n=1.50 and the angle of incidence is 35 find the angle of refraction

1.33 sin i (35)=1.50 sin i(?)

1.33 x sin i (35) /1.50 = 0.509

sin -1 inverse (0.509) = 31

the angle of refraction is 31 sin r (31)

if the sin value is more then 1 it cannot refract and does TIR and shows a error in the calculator as sin-1(1) = 90 degrees which is critical angle

formula for critical angle

sin c = 1/n

n = refractive index

a type of glass has n = 1.50 calculate the critical angle

1/1.50=0.6

sin-1(0.6) = 41.8

41.8 is the critical angle

what are optic fibers used for

they are used for information and carry digital signals in the form of pulses of light

what is cladding

cladding is a layer of glass or plastic that has a lower refractive index then the core

explain the process of TIR in a optic glass fiber

TIR can happen only when the light is in the denser medium, because the angle of incidence has to be large enough that the refracted ray would bend past 90° (the critical angle). When this happens, the light is reflected back into the denser medium instead of escaping. In an optical fiber, the core has a higher refractive index than the cladding, so when light hits the claddings boundary at an angle greater than the critical angle, total internal reflection occurs. This keeps the light trapped inside the core. The cladding’s lower refractive index is essential because it prevents the light from refracting out of the fiber. There is also an outer protective coating, but this layer does not affect the optics; it is only there to protect the fiber physically.

what is the reason for using optic fibers for communication

Optical fibres are used for communication because total internal reflection keeps the light trapped inside the fibre, so signals travel long distances with very little loss. They can carry very high data rates because light has a very high frequency. Optical fibers are also lightweight, secure, and not affected by electrical interference, making them reliable for internet and telephone communication.