Question

The value of Planck's constant is $6.63 \times 10^{-34} Js$. The speed of light is $3 \times 10^{17} nm \, s^{-1}$. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of $6 \times 10^{15} \, s^{-1}$ ?

• A. 75
• B. 10
• C. 25
• D. 50

Answer 1

Answer: (D)

50

Answer 2

$\lambda = \frac{C}{V} = \frac{3 \times 10^{17} nms^{-1}}{6 \times 10^{15} s^{-1}} = 50 nm$