question_answer

If the work function of the metal is \[\phi \] and the frequency of incident light is \[\upsilon \] there is no emission of photoelectrons when

A)  \[\upsilon =\frac{\phi }{h}\]      

B)         \[\upsilon >\frac{\phi }{h}\]

C)  \[\upsilon <\frac{\phi }{h}\]        

D)         \[\upsilon >=\frac{\phi }{h}\]