Out of the following options in which case in the velocity of electron greater than `1.5xx10^(6)`m//s.
{hc=1240 eV-nm}

A H-like species is in some excited state "A" and on absorbing a photon of energy 10.2eV gets promoted to new state B. When the electrons from state "B" return back to ground state directly or indirectly, photons of a fifteen different wavelengths are observed in which only mine photon have energy greater than 10.2.eV. [Given : hc=1240 eV-nm] Find the maximum and minimum wavelenght (in nm) of the emitted fifteen photons.

A H-like species is in some excited state "A" and on absorbing a photon of energy 10.2eV gets promoted to new state B. When the electrons from state "B" return back to ground state directly or indirectly, photons of a fifteen different wavelengths are observed in which only mine photon have energy greater than 10.2.eV. [Given : hc=1240 eV-nm] Find the ionization energy (in eV) of hydrogen like specie.

A beam of electromagnetic radiation of intensity 12.8 xx 10^(-5) W//cm^(2) is comprised of wavelength, lambda = 155 nm . It falls normally on a metal (work function phi = 2eV ) of surfacce area of the 1 cm^(2) . If one in 10^(3) photons ejects total number of electrons ejected in 1 s in 10^(x) . (hc = 1240 eVnm) 1eV = 1.6 xx 10^(-19) J =, then x is _____.

A beam of electromagnetic radiation of intensity 12.8 xx 10^(-5) W//cm^(2) is comprised of wavelength, lambda = 155 nm . It falls normally on a metal (work function phi = 2eV ) of surfacce area of the 1 cm^(2) . If one in 10^(3) photons ejects total number of electrons ejected in 1 s in 10^(x) . (hc = 1240 eVnm) 1eV = 1.6 xx 10^(-19) J =, then x is _____.

A beam of electromagnetic radiation of intensity 12.8 xx 10^(-5) W//cm^(2) is comprised of wavelength, lambda = 155 nm . It falls normally on a metal (work function phi = 2eV ) of surfacce area of the 1 cm^(2) . If one in 10^(3) photons ejects total number of electrons ejected in 1 s in 10^(x) . (hc = 1240 eVnm) 1eV = 1.6 xx 10^(-19) J =, then x is _____.

Compute the force (in vetcor notation ) on an electron moving with velocity vecV = 2.5 xx 10^(6)hati m//s in a magnetic field vecB =(10hati- 6 hatk) xx 10 ^(2) Wb//m^(2) , if charge on an electron e =1.6 xx 10^(-19) coulomb.

On a metal with work function 2.0 eV light of wavelength 400 nm falls, maximum velocity of ejected photoelectron are 6.22xx10^(x)m//s. . Hence x is :

A beam of electromagnetic radiation intensity 6.4xx10^(-5)W//cm^(2) is comprised of wavelength , lambda =310 nm.It falls normally on metal (work function 2 eV) of surface are 1 cm^(2) .If one in 10^(3) photons ejects an electron ,total number of electrons ejected in 1 s is 10^x [hc=1240 eV-nm ,1 eV= 1.6xx10^(-19)J ],the value of x is....

A bulb of 40 W is producing a light of wavelength 620 nm with 80% of efficiency , then the number of photons emitted by the bulb in 20 seconds are : ( 1eV = 1.6 xx 10^(-19) J , hc = 12400 eV )