Physics - Current Electricity Question with Solution | TestHub

Energy liberated in the de-excitation of hydrogen atom from the third level to the first level falls on a photo -cathode. Later when the same photo -cathode is exposed to a spectrum of some unknown hydrogen - like gas, excited to the second energy level, it is found that the de Broglie wavelength of the fastest photoelectrons now ejected has decreased by a factor of 3 . For this new gas, difference of energies of the second Lyman line and the first Balmer line is found to be 3 times the ionization potential of the hydrogen atom. Select the correct statement(s):