Question

Einstein got his Nobel Prize for
A. His theory of relativity
B. Explanation of Photoelectric effect
C. His theory of atomic heats of solids
D. None of the above

Answer 1

Hint: According to the Nobel Foundation's statutes, the Nobel Prize can in such a case be reserved until the following year, and this statute was then applied. Albert Einstein, therefore, received his Nobel Prize for 1921 one year later, in 1922.

Complete step by step solution:
The Nobel Prize in Physics 1921 was awarded to Albert Einstein for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect. This effect can occur in any substance gas, liquid, or solid provided the frequency of the light quantum is of sufficient energy to liberate an electron from its atom and thereby cause ionization.
A postage stamp from Bosnia and Herzegovina issued in 2001 commemorates Einstein's findings. The stamp illustrates a quantum of light $\left( {hv} \right)$ striking a substance, such as a metal plate, and an electron is ejected. The stamp provides the equation describing the photoelectric effect where
\[hv = A + \dfrac{{m{v^2}}}{2}\]
The condition expresses that the light quantum \[\left( {hv} \right)\] is relative to the electron restricting energy (A) or more the active energy of the electron \[({E_K}\; = {\text{ }}1/2\;m{v^2}).\;\] the condition is portrayed backward, that is, the dynamic energy of the photoelectron is corresponding to the light quantum less the electron restricting energy).
Hence the correct answer is an option (B).

Note:
Albert Einstein got his Nobel Prize one year later, in 1922. During the determination cycle in 1921, the Nobel Committee for Physics concluded that none of the year's designations met the models as delineated in the desire of Alfred Nobel.