Question

Consider light of wavelengths 400 nm (UV), 550 nm (green, visible), and 900 nm (infrared). What is the energy associated with a 400 nm (UV) photon, a 550 nm (green, visible) photon, and a 900 nm (infrared) photon?

Answer 1

Answer:

Energy of UV light $=4.95\times 10^{-19}j$

Energy of green light $=3.6\times 10^{-19}j$

Energy of infrared light $=2.2\times 10^{-19}j$

Explanation:

We have given the wavelength of UV light = 400 nm $=400\times 10^{-9}m$ , wavelength of green light = 550 nm and wavelength of infrared = 900 nm

Speed of light $c=3\times 10^8m/sec$

Plank's constant $h=6.6\times 10^{-34}$

Energy of the signal is given by $E=h\nu =h\frac{c}{\lambda }$

So energy of UV light $E=\frac{6.6\times 10^{-34}\times3\times 10^8}{400\times 10^{-9}}=4.95\times 10^{-19}j$

Energy of green light $E=\frac{6.6\times 10^{-34}\times3\times 10^8}{550\times 10^{-9}}=3.6\times 10^{-19}j$

Energy of infrared light $E=\frac{6.6\times 10^{-34}\times3\times 10^8}{900\times 10^{-9}}=2.2\times 10^{-19}j$