Question

he value of Planck’s constant is 6.63 × 10–34Js. The velocity of light is 3 × 108 m/sec. Which value is closest to the wavelength of a quantum of light with frequency of 8 × 1015 sec–1 ?

• A. 5 × 10–18 m
• B. 4 × 10–8 m
• C. 3 × 107 m
• D. 2 × 10–25 m

Answer 1

Answer: (B)

4 × 10–8 m

Answer 2

$\lambda = \frac{c}{v} = \frac{3 \times 10^{8}}{8 \times 10^{15}} = 3.75 \times 10 - 8\lambda = \frac{c}{v} = \frac{3 \times 10^{8}}{8 \times 10^{15}} = 3.75 \times 10^{8}m$