Starting Wave optics from Physics (Pearson) by James S. Walker, today for revision and extra study.

TASKS FOR THE DAY

complete backlog from yesterday ( hehe I knew I wouldn't get everything done lol)

Electrochemistry ( NCERT + videos on Khan Academy)

Coordination chemistry ( NCERT)

Physical education ( another chapter for boards)

Wave optics ( Derivations + formulae)

The speed of a wave (c) Refractive index (n) Wavelength (λ) Frequency (𝑓) c= 3*10^8 m/s c= 𝑓λ v= c/n = 𝑓λ/n

When light moves from one medium into another, its frequency stays the same, while both the speed and wavelength generally change. Example Problem 1:

Orange light of wavelength λ = 600 nm in air enters water having an index of refraction of 𝑛 = 1.33. (a) What is the frequency of this light? (b) What is the speed of the light in the water? (c) What is the wavelength of the light in the water? (d) If you were swimming underwater and looked at this light, what color would you see?

(a) 𝑓= c/λ = 3*10^8 / 600*10^-9 = 5*10^14 (b) v= c/n = 3*10^8 / 1.33 = 2.26*10^8 (c) 𝑓= c/λ => 2.26*10^8 = (5*10^14) λ => λ= 4.52*10^-7 m= 452 nm (d) Trick question. Red, because human eyes pick up on frequency under water. The plane in which the electric field oscillates is called the plane of polarization.

The intensity 𝐼 of a beam of light is the energy per second per square meter carried by the light. It turns out that the intensity is proportional to the square of the electric field amplitude.

We can measure the intensity of a beam of light.

To double the intensity of an electromagnetic wave, you should increase the amplitude of the electric field by a factor of 1.414.

Light waves can be manipulated to control the orientation of the electric field vector. Most light is unpolarized – electric field vectors point randomly in all directions. A polarizer transmits only one component of the electric field vector to create light that is linearly polarized – the electric field is constrained to one plane.