Question

The energy of a photon of radiation having wavelength $3000\mathring{A}$ is nearly:

• A. $6.63\times {10}^{19}J$
• B. $6.63\times {10}^{18}J$
• C. $6.63\times {10}^{16}J$
• D. $6.63\times {10}^{49}J$

Answer 1

The correct option is A $6.63\times {10}^{19}J$

Given wavelength =$3000A^{\circ }$

E=h$\nu$

c=$h\nu$

$v=\frac{c}{\lambda }$

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

=6.626 x 1$0^{-34}$ $\times$ $\frac{3\times 10^8}{3000\times 10^{-9}}$

=6.626 x $\frac{10^8}{10^{-9}}$

=6.626 x 1$0^{-34}$ X $10^8$ X $10^7$

=6.626 x 1$0^{-34}$ X $10^{15}$

E= 6.626 x 1$0^{-34}$ X $10^{19}$Joules.