Question

Planck's constant $6.6\times 10^{- 27}erg-$ second, velocity of light $=3\times 10^{10}cm/s$ , the energy of photon of wave-length $3000\mathring{A} $ will be :

• A. $6.6\times 10^{- 12}erg$
• B. $13.2\times 10^{- 12}erg$
• C. $3.3\times 10^{- 12}erg$
• D. $6.6\times 10^{- 19}erg$

Answer 1

Answer: (A)

$E=\frac{hc}{\lambda }$
$=\frac{6 . 6 \times 10^{- 27} \times 3 \times 10^{10}}{3000 \times 10^{- 8}}=6.6\times 10^{- 12}erg$