Question

# Electrons ejected from the surface of a metal, when light of certain frequency is incident on it, are stopped fully by a retarding potential of 3 volts Photo electric effect in this metallic surface begins at a frequency 6 x 1014s ^{-1} The frequency of the incident light in s^{-1} is [h=6 x 10^{-34}J-sec;charge on the electron=1.6x10^{-19}C]

- 7.5 x 10
^{13}
- 13.5 x 10
^{13}
- 14 x 10
^{14}
- 7.5 x 10
^{15}

^{13}^{13}^{14}^{15}## The correct answer is: 14 x 10^{14}

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