Question

The frequency of the visible light of wave length $6000A.U.$ (Angstrom units) is

• A. $4\times {10}^{14}Hz$
• B. $6000$
• C. $5\times {10}^{10}Hz$
• D. $5\times {10}^{14}Hz$

Answer 1

The correct option is D $5\times {10}^{14}Hz$

$c=f\lambda$
Here $\lambda =6000A.U.$
$=6000\times {10}^{-10}m$
$=6\times {10}^{-7}m$
and $c=3\times {10}^{8}m/s$

$f=\frac{c}{\lambda }$
$=\frac{3\times {10}^8}{6\times {10}^{-7}}$
$=5\times {10}^{14}Hz$