Question

Two different sources of light A and B have wavelength $0.7\mu m$ and $0.3\mu m$ respectively. Then which of the following statement is true.

• A. A has greater energy than B
• B. B has greater energy than A
• C. Both has equal energy
• D. None of the above

Answer 1

The correct option is B B has greater energy than A

${\lambda }_A=0.7\times {10}^{-6}m$,
${\lambda }_B=0.3\times {10}^{-1}m$
$E=\frac{hc}{\lambda }$
${\lambda }_A>{\lambda }_B$
Hence, E_A < E_B