Electron Ejection and Light Nature – Rankers Physics

Photoelectric Effects and deBroglie Equation: Practice Problem & Solution

Assertion (A): Electron from metal surface ejects only when light of particular wavelength will fall on surface. Reason (R): Light shows wave nature.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Photoelectric Effects and deBroglie Equation. Understanding the underlying formula is key to arriving at the correct answer below:

Photoelectric emission occurs only when the incident light's wavelength (\lambda\) is below a specific threshold wavelength (\lambda_0\) (A is true). Light exhibits both wave-like (e.g., diffraction) and particle-like properties (R is true). However, the wave nature of light cannot explain the threshold effect for photoelectric emission. Thus, both A and R are true, but R is not the correct explanation for A.

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