The Einstein photoelectric equation is a mathematical expression derived by Albert Einstein to describe the relationship between the frequency of light and the energy of the electrons emitted during the photoelectric effect.
The equation is given by:
E = hf - W, where
- E = energy of the emitted electrons (in Joules)
- h = Planck's constant (6.62 x 10^-34 Joule-seconds)
- f = frequency of the incident light (in Hertz)
- W = the work function of the material, which is the minimum energy required to remove an electron from the material's surface (in Joules)
Critical Angle
- It is the angle of incidence at which the angle of refraction is equal to 90 degrees.
- The critical angle is an important concept in optics, as it determines the conditions under which total internal reflection occurs.
- When light travels from a medium with a higher refractive index to a medium with a lower refractive index, the angle of refraction approaches 90 degrees as the angle of incidence approaches the critical angle.
- Beyond the critical angle, all of the light is reflected back into the first medium and does not pass through into the second medium.