Question
Physics Question on Photoelectric Effect
The work function of a metal is 1eV. Light of wavelength 3000? is incident on this metal surface. The velocity of emitted photoelectrons will be
A
10ms−1
B
1×103ms−1
C
1×104ms−1
D
1×106ms−1
Answer
1×106ms−1
Explanation
Solution
Ekmax=(Ephoton−W)eV
=(3×10−712.42×10−7−1)eV
=(4−1)eV
Ekmax=3eV=3×1.6×10−19J
21mvmax2=3×1.6×10−19
vmax2=9.1×10−313×2×1.6×10−19
vmax2=1012
vmax=106ms−1