A monochromatic light beam is incident on the surface of a metal having a work function of 2.50 eV.If a 1.0-V stopping potential is required to make the electron current zero,what is the wavelength of light? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J) A)355 nm B)423 nm C)497 nm D)744 nm

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Quizplus · Accepted Answer

The energy of the incident photons is equal to the work function plus the stopping potential energy. Using the photoelectric equation: $E = \text{Work function} + eV$, where $E = \frac{hc}{\lambda}$. Solving for $\lambda$, we find $\lambda = \frac{hc}{\text{Work function} + eV}$. Substituting the given values, $\lambda = \frac{6.626 \times 10^{-34} \times 3.00 \times 10^8}{(2.50 + 1.0) \times 1.60 \times 10^{-19}}$, which gives approximately 355 nm.

A Monochromatic Light Beam Is Incident on the Surface of a Metal