The threshold wavelength of tungsten is 2.76 x 105 cm. (a) Explain why no photoelectrons are emitted when the wavelength is more than 2.76 x 105 cm. (b) What will be the maximum kinetic energy of electrons ejected in each of the following cases (i) if ultraviolet radiation of wavelength 2 = 1.80 x 105 cm and (ii) radiation of frequency 4x1015 Hz is made incident on the tungsten surface.10. Photocurrent recorded in the micro ammeter in an experimental set-up of photoelectric effect vanishes when the retarding potential is more than 0.8 V if the wavelength of incident radiation is 4950 A. If the source of incident radiation is changed, the stopping potential turns out to be 1.2 V. Find the work function of the cathode material and the wavelength of the second source