Question: Q. 12. The given graph shows the variation of photoelectric current $(I)$ with the applied voltage $(V)$ for two different materials and for two different intensities of the incident radiations. Identify and explain using Einstein’s photoelectric equation the pair of curves that correspond to (i) different materials but same intensity of incident radiation, (ii) different intensities but same material.
(V)
R[OD East 2016]
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Solution:
Ans. (i) $(1,2)$ correspond to same intensity but different material.
$(3,4)$ correspond to same intensity but different material
As saturation currents are same and stopping potentials are different.
(ii) $(1,3)$ correspond to different intensities but same material.
$(2,4)$ correspond todifferent intensities but same material. As stopping potentials are same but saturation currents are different.
[CBSE Marking Scheme 2016]
