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, $v=\frac{c}{\lambda }=\frac{3\times 10^{8}m{s}^{-1}}{6300\times 10^{-10}m}$
$=4.761\times 10^{14}{s}^{-1}$