Einstein’s Equation - Particle Nature of Light

The energy of photon of wavelength X is_____ .

[h = Planck’s constant, c = speed of light in vacuum]

(a)hcλ

(b)hλ/c

(c)λ/hc

(d)hc/λ

When radiations of wavelength λ₁ and λ₂ are incident on certain photosensitive, such that E₁ > E₂ . Then Planck's constant 'h' is ......................... .

(C = Velocity of light).

1. `((E_1 - E_2)(lambda_1 - lambda_2))/(C(lambda_1 * lambda_2))`
2. `((E_1 - E_2)lambda_1C)/((lambda_1 - lambda_2)lambda_2)`
3. `((E_1 - E_2)lambda_1lambda_2)/(C(lambda_2 - lambda_1))`
4. `((lambda_1 - lambda_2)C)/((E_1 - E_2)lambda_1 * lambda_2)`

The threshold wavelength of silver is 3800Å. Calculate the maximum kinetic energy in eV of photoelectrons emitted, when ultraviolet light of wavelength 2600Å falls on it.

(Planck’s constant, h =6.63 x 1O^-34J.s.,

Velocity of light in air, c = 3 x 10⁸ m / s)

The photoelectric threshold wavelength of a metal is 230 nm. Determine the maximum kinetic energy in joule and in eV of the ejects electron for the metal surface when it is exposed to a radiation of wavelength 180 nm.

[Planck’s constant : h = 6.63 * 10^-34 Js, Velocity of light : C = 3 * 10⁸ m/s.]

Find the value of energy of electron in eV in the third Bohr orbit of hydrogen atom.

(Rydberg's constant (R) = 1· 097 x 10⁷m ^{- 1},
Planck's constant (h) =6·63x10^-34 J-s,
Velocity of light in air (c) = 3 x 10⁸m/ s.)

Find the wave number of a photon having energy of 2.072 eV

Given : Charge on electron = 1.6 x 10^-19 C,

           Velocity of light in air = 3 x 10⁸ m/s,

           Planck’s constant = 6.63 x 10^-34 J-s.

The momentum of a photon of de Broglie wavelength 5000Å is _______.

[Planck’s constant = 6.63 x10^-34 J.s.]

(A) 1.326 x10^-28 kg-m/s

(B) 7.54 x10^-28 kg-m/s

(C) 1.326 x10^-27 kg-m/s

(D) 7.54 x10^-27 kg-m/s

The work function for a metal surface is 2.2eV. If the light of wavelength 5000Å is incident on the surface of the metal, find the threshold frequency and incident frequency. Will there be an emission of photoelectrons or not? (c = 3 x 10⁸ m/ s, 1eV = 1.6x10^-19 J , h = 6.63 x 10^-34 J.s.)