When a light of wavelength ' ' falls on the emitter of a photosensitive surface, maximum speed of emitted photoelectrons is 'V'. If the incident wavelength is changed to ' 2 /3 ', maximum speed of emitted photoelectrons will be

Step-by-step solution

According to Einstein's photoelectric equation, the maximum kinetic energy of emitted photoelectrons is given by 1 2 mV^2 = hc - When the incident wavelength is changed to 2 3 , the new maximum kinetic energy is 1 2 mV'^2 = hc 2 3 - = 3hc 2 - Substituting hc = 1 2 mV^2 + into the above equation, we get 1 2 mV'^2 = 3 2 ( 1 2 mV^2 + ) - 1 2 mV'^2 = 3 2 ( 1 2 mV^2 ) + 2 Since the work function > 0 , it follows that 1 2 mV'^2 > 3 2 ( 1 2 mV^2 ) V'^2 > 1.5 V^2 V' > V(1.5)^ 1 2 Thus, the maximum speed of emitted photoele