A beam of electrons of energy E scatters from a target having atomic specing of 1Å. The first maximum intensity occurs at `theta = 60^@`. The E (in eV) is ___________
(Planck constant `h = 6.64 xx 10^(-34) Js`,
`1eV = 1.6 xx 10^(19)J`,
electron mass `m = 9.1 xx 10^(-31) kg`)

The frequency of a Photon having energy 100 eV is ...... Hz. (take h = 6.62 xx 10^(-34) Js, 1eV = 1.6 xx 10^(-19) J)

The radius of the second Bohr orbit for hydrogen atom is________. [Plank's constant, h = 6.6262 xx 10^-34 Js mass of electron = 9.109 xx 10^-31 kg charge on electron, e = 1.602 xx 10^-19 C]

Calculate momentum of electron, if their wavelength is 1overset @ A . Given, Planck's constant h=6.625 xx 10^(-34) Js , mass of electron m=9.1 xx 10^(-31) kg.

The work function of a metallic surface is 2.5 eV. Ultraviolet light of wavelength 2000Å is allowed to be incident on the metallic surface. Calculate Stopping potential. (Given Planck's constant h = 6.63 xx 10^(-34) J-s , electronic charge e = 1.6 xx 10^(-19) C, electron mass m = 9.1 xx 10^( -31) kg

The kinetic energy of an electron is 4.55 xx 10^(-25)J . Calculate the wavelength . [h = 6.6 xx 10^(-34)Js , mass of electron = 9.1 xx 10^(-31)kg]

Calculate momentum of electron, if their wavelength is 2 overset @ A . Given, Planck's constant h=6.625 xx 10^(-34) Js , mass of electron m=9.1 xx 10^(-31) kg.