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The work function of Cs is 2.14eV. Find (a) threshold frequency for Cs (b) Wavelength of incident light if the photo current is brought to zero by stopping potential of 0.6 V. |
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Answer» Wave function ω = 2.14eV (a) Threshold frequency ω = hν0 v0 = ω/h = (2.14 x 1.6 x 10-19)/ (6.62 x 10-34) = 5.7 x 1014 Hz (b) As kmax = eV0 = 0.6eV Energy of photon E = kmax + ω = 0.6eV + 2.14eV = 2.74 eV Wave length of photon λ = hc/ E = (6.62 x 10 -34 x 3 x 10 -8)/ (2.74 x 1.5 x 10 -19) = 4530 Å |
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