The photoelectric work function for a metal surface is 4.125

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The photoelectric work function for a metal surface is 4.125 eV. The cut off wavelength for this surface is

1. 4125 Å
2. 3000 Å
3. 6000 Å
4. 2062.5 Å

Correct Option: B

Let λ₀ be cut off wavelength.
Work function

=	hc	= 4.125 × 1.6 × 10^-19
	λ₀

λ₀ =	6.626 × 10^-34 × 3 × 10⁸	= 3000 Å
	4.125 × 1.6 × 10^-19