Question

Albert Einstein used corpuscular theory to explain
A) $E=m{c}^2$
B) The photoelectric effect
C) Quantization of charge
D) Magic of light

Answer 1

Hint: In $$1637$$, Descartes described a Theory about the emission of small particles called corpuscular theory of light. These small particles are called Corpuscles and they travel in a straight path with finite velocity and momentum also. This theory used to describe the particle nature of light as photoelectric effect and Compton Effect.

Complete step by step answer:
In $$1900$$, Planck introduced quantum physics to the world by which many unsolved problems and mysteries were solved.
The problem of behaviour of light was also solved by this theory. Light is only considered as a wave, which always moves in a straight path.
Einstein, in $$1905$$, published the paper in which he described that the light travels in the form of bundles or packets. Each of this bundle or packet has the energy $h\upsilon$. On the basis of corpuscular theory he explained that these little bundles or packets are called photons and described the phenomenon of Photoelectric effect.
In Photoelectric effect, Einstein described that when light ray incident on any metal then it starts emitting electrons from the surface of the metal because according to the particle nature of light, light travels in the form of quanta having energy $h\upsilon$ where $$h$$ is Planck's Constant and $\upsilon$ is the frequency of incident light.
The emission of electrons from the surface of any metal due to the incident light ray is called Photoelectric effect. It was firstly discovered by Hertz.

Hence option B is correct.

Note:
Every metal has a definite work function. Photoelectric effect occurs only if the energy of incident light rays is greater than the work function of the surface. For understanding Photoelectric effect these are important points
1) Work function- The minimum energy that is required for emission of one electron from the metal surface.
2) Threshold frequency- The minimum frequency of light which is required for emission of one electron from the metal surface.