Speed of Light and Refraction

Dr. Johnson Seigelman explains the speed of light in various media, focusing on the index of refraction, which is the ratio of the speed of light in a vacuum to that in a material. The lesson covers how waves change speed and wavelength when moving between media, using mathematical equations and practical examples, such as light traveling through air and diamond. The video concludes with a review of the key concepts, emphasizing that a higher index of refraction results in a slower speed of light.

What is the equation used to define the index of refraction?

• n = v/c

• n = c * v

• n = c/v

• n = v * c

What happens to the speed of light when it enters a denser medium?

• It slows down

• It disappears

• It remains constant

• It speeds up

Which of the following materials has an index of refraction close to 1?

• Diamond

• Air

• Water

• Glass

What remains constant when a wave passes from one medium to another?

• Speed

• Frequency

• Wavelength

• Amplitude

How does the wavelength change when the speed of light decreases in a new medium?

• It decreases

• It doubles

• It increases

• It remains the same

In the example of air and diamond, what is the approximate speed of light in diamond?

• 1.500 x 10^8 m/s

• 3.000 x 10^8 m/s

• 1.239 x 10^8 m/s

• 2.998 x 10^8 m/s

What is the index of refraction for diamond as mentioned in the example?

• 1.000

• 2.419

• 1.500

• 3.000

Why is the speed of light in air almost the same as in a vacuum?

• Because air is denser than a vacuum

• Because air is a solid

• Because air has a high index of refraction

• Because air has an index of refraction close to 1

What is the relationship between the index of refraction and the speed of light in a material?

• Higher index means lower speed

• Index and speed are unrelated

• Index does not affect speed

• Higher index means higher speed

What is the speed of light in a vacuum?

• 1.239 x 10^8 m/s

• 2.998 x 10^8 m/s

• 2.500 x 10^8 m/s

• 3.000 x 10^8 m/s