According to Einstein's photoelectric equation
kmax=λhc−ϕ
⇒k1=8001230−ϕ...(1)
And ⇒k2=5001230−ϕ
Since, k2=2k1
⇒2k1=5001230−ϕ...(2)
Eliminating k1 from (1) and (2) we get
0=5001230−4001230+ϕ
⇒ϕ=0.615eV
JEE Main 2022 — Physics Modern Physics
A metal exposed to light of wavelength 800nm and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of photo-electron doubles when light of wavelength 500nm is used. The work function of the metal is
(Take hc=1230eV−nm).
Held on 25 Jul 2022 · Verified 6 Jul 2026.
1.537eV
2.46eV
0.615eV
1.23eV
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