Question

(9)
( lambda=25 mathrm{mm} )
( a_{23} lambda=25 times 10^{-6} mathrm{m} )
( begin{aligned} text { ware } n theta cdot &=frac{1}{lambda} &=frac{10^{6}}{25}+m-1 &=0 cdot 04 times 10^{6} mathrm{m}^{-1} &=4 times 10^{4} &=4 times 10^{2} mathrm{cm}-1 end{aligned} )

# | 5 Wavelength of a light beam is 25 um, its wave number is - (1) 4.0 x 102 cm-1) (2) 4.0 x 106 cm-1 4(2) 4.0 x 106m-1 (4) 25.0 x 104 cm-1

Solution