Page 07 10. Ultraviolet radiation of frequency 7·70 × 1014 Hz is incident on the surface of a metal. Photoelectrons are emitted from the surface of the metal. The maximum kinetic energy of an emitted photoelectron is 2·67 × 10−19 J. The work function of the metal is A 1·07 × 10−19 J B 2·44 × 10−19 J C 2·67 × 10−19 J D 5·11 × 10−19 J E 7·78 × 10−19 J. 11. A student makes the following statements about waves from coherent sources. I Waves from coherent sources have the same velocity. II Waves from coherent sources have the same wavelength. III Waves from coherent sources have a constant phase relationship. Which of these statements is/are correct? A I only B II only C I and II only D I and III only E I, II and III [Turn over