Which of the following statements is (are) NOT true about the emission of the photoelectrons from metallic surfaces?
i. all metallic surfaces emits the same number of photoelectrons in a given light
ii. most metallic surfaces emit the same number of photoelectrons in visible and infra-red light
iii. a metallic surface emits photoelectrons only if the frequency of the incident light is higher than its own characteristics threshold frequency
A galvanometer of resistance 5.0Ω has full-scale deflection for a current of 100mA. How would its range be extended to 1.0A? By placing a resistance of
