Refraction and Total Internal Reflection -2

Why does the pencil appear bent?

• Light rays travelling from parts of the pencil above the water bend away from the normal and appear closer to the horizontal surface, thus making the pencil appear broken.

• Light rays travelling from parts of the pencil above the water bend towards from the normal and appear closer to the horizontal surface, thus making the pencil appear broken.

• Light rays travelling from parts of the pencil under the water bend away from the normal and appear closer to the horizontal surface, thus making the pencil appear broken.

• Light rays travelling from parts of the pencil under the water bend towards from the normal and appear closer to the horizontal surface, thus making the pencil appear broken.

What does part #2 in the system represent?

• Light signals are what carries information in fiber optics

• Digital signals are sent through fiber optic cables

• Total internal reflection keeps the light inside of the cable

• Lasers are the source of light that we send in fiber optics

• Glass or plastic fiber optic cables carry information as light

Tags

NGSS.MS-PS4-2

If the light is travelling from glass with a wavelength of 600nm to diamond, then what is the wavelength in the diamond? (n of glass = 1.5 and n of diamond = 2.4)

• 236nm

• 256nm

• 610nm

• 375nm

After which angle of incidence will the light go through total internal reflection in the fibre optic pipe if the n for the pipe is 1.2.

AND what is the angle of refraction?

Outside is air. (Sin 60 - 0.87, Sin 45 = 0.7, Sin90 = 1, Sin 30 = 0.5, Sin 37 = 0.6, Sin 0 = 0, Sin, Sin 53 = 0.8, Sin 44 = 0.7, Sin 78.5 = 0.98)

• Incident angle = 78.5 degrees, Angle of refraction = 45

• Incident angle = 44 degrees, Angle of refraction = 37

• Incident angle = 60 degrees, Angle of refraction = 53

• Incident angle = 78.5 degrees, Angle of refraction = 30

• Incident angle = 44 degrees, Angle of refraction = 78.5

As shown in the figure, the light beam makes an angle of 20 degrees with the normal inside linseed. Calculate the incident angle in air (theta) and the refracted angle in water (theta prime).

(n for linseed = 1.5, n for water = 1.3, n for air = 1, Sin 20 = 0.34, Sin 23 = 0.39, Sin 30 = 0.5, Sin 45 = 0.7, Sin 48.6 = 0.75, sin 56 = 83, Sin 60 = 0.87, Sin 37 = 0.6)

• Theta = 23 degrees, Theta prime = 30 degrees

• Theta = 30 degrees, Theta prime = 45 degrees

• Theta = 48.6 degrees, Theta prime = 37 degrees

• Theta = 30 degrees, Theta prime = 23 degrees

^{What is the refractive index of a fibre optic pipe if the critical angle is 30 degree?}

^{Outside is air.}

• 2.0

• 1.7

• 2.4

Tags

NGSS.HS-PS4-5

Choose the correct statement that describes what happens to the ray of light if the critical angle is 48^o and the angle of incidence is 48^o

• refract

• totally internally reflect

• travel along the boundary

Tags

NGSS.HS-PS4-3

^{Which one is true for the formation of a mirage?}

• The light first goes through TIR and then passes through the colder layers of air to hotter layers. (TIR is total internal reflection)

• The light first goes through TIR after passing through the colder layers of air to hotter layers.

• The light first goes through TIR and then passes through the hotter layers of air to colder layers.

What is the most prominent use of Fiber Optics today?

• Phones
• Television Screens
• The Internet
• MRI imaging

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-5

Which is true?

• nb > nc > na

• nc > nb > na

• na > nc > nb

• nb > na > nc

• none of the above