NEET Physics Question - Modern Physics - Photoelectric Effects and deBroglie Equation

Assertion (A): A metallic surface is irradiated by monochromatic light of frequency \(nu > nu_0\) (the threshold frequency). The maximum kinetic energy and stopping potential are \(K_{\text{max}}\) and \(V_s\) respectively. If the frequency of incident on the surface is doubled, both \(K_{\text{max}}\) and \(V_s\) are more than doubled.

Reason (R): The maximum kinetic energy and the stopping potential of photoelectrons emitted from a surface are linearly dependent on the frequency of incident light.

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:

Concept: Photoelectric effect and linear dependence.
Formula: \(K_{\text{max}} = h\nu - h\nu_0\) and \(V_s = \frac{h\nu}{e} - \frac{h\nu_0}{e}\) where \(h\nu_0\) is the work function.
Solution: Both \(K_{\text{max}}\) and \(V_s\) are linearly dependent on frequency \(\nu\) with a positive slope and a negative intercept (work function term). Due to this negative intercept, if \(\nu\) is doubled, \(K_{\text{max}}\) and \(V_s\) will increase by more than double. Thus, both (A) and (R) are true, and (R) correctly explains (A).

Rankers Physics

Photoelectric Effect: Doubling Frequency

Solution:

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