THE ALKALI METAL PHOTOELECTRIC CELL 



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on the photoelectric effect are shown in Figure 7, where the symbol II 

 indicates that the electric vector is in the plane of incidence, the 

 s\nibol ± thai it is perpendicular to this plane. 



0° 20° 40° 60° 8c° 



Angle of Incidence 



Fig. 7 — Photoelectric emission from a specular surface of solid potassium, and from a 



thinly coated platinum plate, at various angles of incidence; electric vector in plane 



of incidence (||); electric vector perpendicular to the plane of incidence (x). 



Distribution of Response According to Wave Length 



When the exciting light is incident either perpendicularly on a 

 specular alkali metal surface, or at a high angle of incidence with the 

 plane of polarization such that the electric vector is parallel to the 

 surface, the response for equal intensities of monochromatic radiation 



