The stopping potential \( V_0 \) is related to the maximum kinetic energy of the emitted photoelectrons through the equation:
\( KE_{\text{max}} = h\nu - \phi_0 = eV_0, \)
where:
- \( h \) is Planck’s constant,
- \( \nu \) is the frequency of the incident light,
- \( \phi_0 \) is the work function of the emitter material,
- \( e \) is the elementary charge.
Key points to note:
1. The stopping potential \( V_0 \) depends on the frequency of the incident light (\( \nu \)) but is independent of the intensity of the light. Increasing the intensity of the incident light increases the number of emitted photoelectrons but does not affect their maximum kinetic energy or the stopping potential.
2. The stopping potential is also influenced by the nature of the emitter material since different materials have different work functions (\( \phi_0 \)).
Therefore, statement (3) is incorrect, as \( V_0 \) does not increase with an increase in the intensity of the incident light.
Einstein's Explanation of the Photoelectric Effect:
Einstein explained the photoelectric effect on the basis of Planck’s quantum theory, where light travels in the form of small bundles of energy called photons.
The energy of each photon is hν, where:
The number of photons in a beam of light determines the intensity of the incident light.When a photon strikes a metal surface, it transfers its total energy hν to a free electron in the metal.A part of this energy is used to eject the electron from the metal, and this required energy is called the work function.The remaining energy is carried by the ejected electron as its kinetic energy.
Let $ P_n = \alpha^n + \beta^n $, $ n \in \mathbb{N} $. If $ P_{10} = 123,\ P_9 = 76,\ P_8 = 47 $ and $ P_1 = 1 $, then the quadratic equation having roots $ \alpha $ and $ \frac{1}{\beta} $ is: