Question

please let me answer immediately

Answer 1

it izs namerical
so i am not find

Answer 2

Wavelength of light = 6400 A

$1A= {10}^{ - 10} \: m \\ \\ 6400A = 6400 \times {10}^{ - 10} \: m = 6.4 \times {10}^{ - 7} \: m$

$1m = {10}^{6} \: micron \\ \\ 6.4 \times {10}^{ - 7} \: m = 6.4 \times {10}^{ - 7} \times {10}^{6} = 0.64 \: micron$

Hence,

$6400A = 6.4 \times {10}^{ - 7} \: m = 0.64 \: micron$