Threshold frequency for a metal is \[{{10}^{15}}\]Hz. Light of \[\lamb – McqOptions

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1.	Threshold frequency for a metal is \[{{10}^{15}}\]Hz. Light of \[\lambda =4000{AA}\]falls on its surface. Which of the following statements is correct
A.	No photoelectric emission takes place
B.	Photo-electrons come out with zero speed
C.	Photo-electrons come out with 103 m/sec speed
D.	Photo-electrons come out with 105 m/sec speed
Answer» B. Photo-electrons come out with zero speed

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