Origins of quantum physics, photoeffect
Answers are for parents and teachers.
1
A photon has wavelength 124 nm. What is its energy in eV? (hc = 1240 eV·nm)
10
2
In the photoeffect the photon is 6 eV and the work function 4 eV. What is the stopping voltage in V?
2
3
The red limit is 310 nm. What is the work function in eV? (hc = 1240 eV·nm)
4
4
A star is at T = 2898 K. What is λ_m in nm?
1000
5
Why does even very weak ultraviolet light (ν > ν_min) produce a photocurrent almost at once?
An electron gets its energy from a single photon; there is no need to «accumulate» energy, so there is no delay.