A mercury lamp is a convenient source for studying frequency dependence of photoelectric emission, since, it gives a number of spectral lines ranging from the UV to the red end of the visible spectrum. In our experiment with rubidium photo-cell, the following lines from a mercury source were used
λ1=3650˚A,λ2=4358˚A,λ3=4358˚A,λ4=5461˚A,λ5=6907˚A.
The stopping voltages, respectively, were measured to be:
V01=1.28V, V02=0.95V, V03=0.74V, V04=0.16V,V05=0V,
Determine the value of Plancks constant h, the threshold frequency and work function for the material.