The work function, ϕ₀ = 6.2 eV. Stopping potential V₀ = 5V. Calculate the wavelength of the incident radiation.

λ = hc / eV₀ + ϕ₀
λ = 6.62 × 10^-34 × 3 × 10^8 / 1.6 × 10^-19 × (5 + 6.2)
λ = 19.86 × 10^-26 / 17.92 × 10^-19 = 1.10 × 10^-7 m
Thus the wavelength of the incident radiation lies in the ultraviolet region.

Correct answer: λ = 19.86 × 10^-26 / 17.92 × 10^-19 = 1.10 × 10^-7 m

Solution

The wavelength of the incident radiation is calculated using the photoelectric equation: E = hc/λ = e(V₀ + ϕ₀). Substituting the given values, λ = (6.62 × 10^-34 × 3 × 10^8) / (1.6 × 10^-19 × (5 + 6.2)) = 1.10 × 10^-7 m.

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