Refraction and total internal reflection

• What is the topic of Unit One in B Tech applied science?

  Physics
• What is the main focus of the video discussed?

  Refraction and total internal reflection
• What is the first phenomenon mentioned in the quiz?

  Reflection
• What happens to a wave when it enters a denser medium?

  It bends towards the normal
• What does the term "normal" refer to in the context of refraction?

  A line at right angles to the surface
• Why does a wave bend towards the normal when entering a denser medium?

  Because the wave slows down
• What happens to a wave when it goes from glass to air?

  It bends away from the normal
• Why does a wave bend away from the normal when entering a less dense medium?

  Because the wave speeds up
• What is the speed of light in a vacuum?

  $3 \times 10^8 \text{ m/s}$
• What is the speed of light in water?

  $2.25 \times 10^8 \text{ m/s}$
• What does the refractive index indicate?

  How much light slows down in a medium
• What is the refractive index of water?

  1.33
• How is the refractive index calculated?

  By dividing speed of light in vacuum by speed in medium
• If the speed of light in water is $2.25 \times 10^8 \text{ m/s}$, what is the speed of light in a very dense material like diamond?


  $1.25 \times 10^8 \text{ m/s}$
• What is the relationship between angles of incidence and refraction in the context of refractive index?

  Sin I / Sin R equals the refractive index
• What do the angles I and R represent?

  I is the angle of incidence, R is the angle of refraction
• How are angles I and R measured?

  Between the ray and the normal
• What happens when the angle of incidence reaches the critical angle?

  The wave reflects instead of refracting
• What is total internal reflection?

  Reflection of light within a denser medium
• What is the critical angle?

  The angle at which total internal reflection occurs
• How is the critical angle calculated?

  Using the equation $\sin C =$$\frac{1}{n}$
• What is the critical angle for water?

  48.8 degrees
• What is the critical angle for glass?

  41.8 degrees
• What is the critical angle for diamond?

  24.6 degrees
• What are the uses of fiber optic cables?

  • Communication (digital signals)
  • Endoscopes for medical imaging
• How do optical fibers work?

  • Light travels in straight lines
  • Total internal reflection keeps light inside
  • Allows light to be directed around corners
• What is the significance of total internal reflection in optical fibers?

  • Enables efficient light transmission
  • Prevents light from escaping the fiber
  • Allows for communication and medical applications
• What happens to light when it travels through a fiber optic cable?

  • Light reflects off the inside of the fiber
  • Light bounces around and exits at the other end
• What is the relationship between the critical angle and refractive index?

  • Critical angle decreases as refractive index increases
  • Higher refractive index means light is more trapped
• What is the effect of increasing the angle of incidence in water?

  • Angle of refraction increases until critical angle
  • Beyond critical angle, light reflects instead of refracting
• What is the role of the normal line in refraction?

  • Acts as a reference for measuring angles
  • Helps determine how light bends at interfaces
• What is the significance of the speed of light in different mediums?

  • Determines how much light bends
  • Affects the refractive index of the medium
• How does the density of a medium affect light behavior?

  • Denser mediums slow down light
  • Light bends towards the normal in denser mediums
• What is the importance of the refractive index in optics?

  • Indicates how much light slows down
  • Essential for calculating angles in refraction