Question

Calculate the energy of a quantum of radiation of wavelength 250 nm.​

Answer 1

Answer:

Thus, the energy associated with the wavelength, λ = 250 × 10−9 m is equal to the7. 95 × 10−19 J. Hence, (A) is the correct option. This is an Einstein equation of energy.

Answer 2

$\sf\lambda \: = 250 \: nm \:$

$\sf \: \: \: \: \: = 250 \times {10}^{ - 9} m$

According to Quantum theory ,

$\sf E = \frac{h c}{\lambda}$

where

• $\sf E \rightarrow Energy$
• $\sf c \rightarrow speed of light$
• $\sf h \rightarrow Planck's constant$
• $\sf \lambda \rightarrow wavelength$

$\sf E = \: \frac{6.626 \times {10}^{ - 34}3×{10}^{8}} {250 \times {10}^{ - 9}}$

$\sf \: \: \: \: \: = 7.95 \times {10}^{ - 19} J$