Question

if kinetic energy of photons is increased 9 times ,the wavelength of the de broglie wave associated with it would be

Answer 1

wavelength of debrogile wave =h/√2m(K.E.).
here in the equation, h is Planck's constant , m is mass of substance and K.E. is kinetic energy . So if K.E. increases by 9 times then new wavelength of debrogile wave =h/√2m(9K.E.) =h/3√2mK.E. = 1/3(initial wavelength of debrogile wave). So it becomes one third of initial value. Hope it helps you....