For photoelectric emission, tungsten requires light of 2300 $\stackrel{\mathrm{o}}{\mathrm{A}}$. If light of 1800 $\stackrel{\mathrm{o}}{\mathrm{A}}$ wavelength is incident then emission

In tungsten, photoemission take place with a light of wavelength 2300 $\stackrel{\mathrm{o}}{\mathrm{A}}$. ,ts emission of electron is inversely proportional to wavelength, all the wavelengths smaller then 2300 $\stackrel{\mathrm{o}}{\mathrm{A}}$ will cause emission of electrons.