Question

Calculate the wave number and frequency of orange radiation having wavelength $6300\,\mathring{A}$.

• A. $1.587 \times 10^{8} m ^{-1}, 4.761 \times 10^{16} s-1$
• B. $1.587 \times 10^{4} m ^{-1}, 4.761 \times 10^{14} s-1$
• C. $1.587 \times 10^{6} m ^{-1}, 4.761 \times 10^{14} s-1$
• D. $1.587 \times 10^{6} m ^{-1}, 4.761 \times 10^{16} s-1$

Answer 1

Answer: (C)

For orange radiation $(EMR)$ of $\lambda=6300\,\mathring{A}$.
(i) Wave number,
$\bar{v} =\frac{1}{\lambda}=\frac{1}{6300 \mathring{A}}=\frac{1}{6300 \times 10^{-10} m }$
$=1.587 \times 10^{6} m ^{-1}$
(ii) Frequency, $v=\frac{c}{\lambda}=\frac{3 \times 10^{8} ms ^{-1}}{6300 \times 10^{-10} m }$
$=4.761 \times 10^{14} s^{-1}$