Advertisements
Advertisements
प्रश्न
- Calculate the energy and momentum of a photon in a monochromatic beam of wavelength 331.5 nm.
- How fast should a hydrogen atom travel in order to have the same momentum as that of the photon in part (a)?
उत्तर
(a) Energy = E = `"hc"/λ`
or, E = `(6.6 xx 10^-34 xx 3 xx 10^8)/(331.5 xx 10^-9)`
∴ E = 6 × 10−19 J
Momentum = p = `"h"/λ`
Or, p = `(6.6 xx 10^-34)/(331.5 xx 10^-9)`
∴ p = 2 × 10−27 kg.m/s
(b) Momentum of Hydrogen atom = p = 2 × 10−27 kg.m/s
p = mv
Or, v = `"p"/"m"`
Or, v = `(2 xx 10^-27 "kg.m/s")/(1 "a.m.u")`
Or, v = `(2 xx 10^-27 "kg.m/s")/(1.66 xx 10^-27 "kg")`
∴ v = 1.2 m/s
संबंधित प्रश्न
The energy of photon of wavelength X is_____ .
[h = Planck’s constant, c = speed of light in vacuum]
State two important properties of photon which are used to write Einstein’s photoelectric equation.
With reference to the photoelectric effect, define threshold wavelength
Write the basic features of photon picture of electromagnetic radiation on which Einstein’s photoelectric equation is based.
Write Einstein’s photoelectric equation.
According to Einstein’s model minimum energy needed for the electron to escape from a metal surface having work function ϕ0, the electron is emitted with maximum kinetic energy, Kmax = ______.
Which of the following graphs correctly represents the variation of maximum kinetic energy (Ek) of photoelectrons with the frequency (𝜈) of the incident radiation?
A police van moving on a highway with a speed of 30 km/h fires a bullet at a thief's car speeding away in the same direction with a speed of 192 km/h. If the muzzle speed of the bullet is 150 m is, with what speed does the bullet hit the thief's car?
The wavelength of matter is independent of
(i) A ray of light incident on face AB of an equilateral glass prism, shows minimum deviation of 30°. Calculate the speed of light through the prism.
(ii) Find the angle of incidence at face AB so that the emergent ray grazes along the face AC.
