Light of wavelength `4000 Å` falls on a photosensitive metal and a negative `2 V` potential stops the emitted electrons. The work function of the material ( in eV) is approximately `( h = 6.6 xx 10^(-34) Js , e = 1.6 xx 10^(-19) C , c = 3 xx 10^(8) ms^(-1))`

The photoelectric threshold wavelength for Potassium having work function of 2eV is.......... (Take h= 6.6 xx 10^(-34) J s. 1 eV = 1.6 xx 10^(-19) J , C = 3 xx 10^8 Ms^(-1) )

The wavelength of most energetic X-rays emitted when a metal target is bombarded by 40 keV electrons, is approximately (h=6.62xx10^(-34)J-sec,1eV=1.6xx10^(-19)J,c=3xx10^(8)m//s) .

When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is "_________"Å (Round off to the Nearest Integer). [Use : sqrt3 = 1.73 , h - 6.63 xx 10 ^(-34) Js m _(c ) = 9.1 xx 10 ^(-31) kg , c =3.0 xx 10 ^(8) ms ^(-1) ,1eV = 1. 6 xx 10 ^(-19))]

A metal has a work function of 2eV. It is illuminated by monochromatic light of wavelength 500 nm, calculate (i) the threshold wavelength, (ii) the maximum energy of photoelectrons, (iii) The stopping potential. Given Planck's constant h = 6.6 xx 10^(-34)J.s , charge on electron e = 1.6 xx 10^(-19) C and 1eV = 1.6 xx 10^(-19)J

An X-ray tube operates on 30 kV. The minimum wavelength emitted is h = 6.6 xx 10^(-34) Js, c = 3 xx 10^(8) m/s, e = 1.6 xx 10^(-19) C.

If de Broglie wavelength of an electron is 0.5467 Å, find the kinetic energy of electron in eV. Given h=6.6xx10^(-34) Js , e= 1.6xx10^(-19) C, m_e=9.11xx10^(-31) kg.