The work function of sodium is 2.3 eV — JEE Physics
The work function of sodium is 2.3 eV. Find the maximum kinetic energy of photoelectrons when light of frequency $7.5 \times 10^{14}$ Hz falls on it. ($h = 6.63 \times 10^{-34}$ J·s)
1 Answer
NRNikhil Rao
✓ Accepted
· 2mo ago
▲ 31
$$E_{photon} = hf = 6.63\times10^{-34} \times 7.5\times10^{14} = 4.97\times10^{-19} J = 3.11 eV$$
$$KE_{max} = E_{photon} - \phi = 3.11 - 2.3 = 0.81 eV$$
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Discussion (2)
N
Tip for others: you can verify the answer quickly by checking the units.
C
Does this approach generalise to the JEE Advanced version of this question?