Question

The ratio of SI unit to the CGS unit of planck's constant is :

• A. ${10}^7:1$
• B. ${10}^4:1$
• C. ${10}^6:1$
• D. $1:1$

Answer 1

Answer: (A)

${10}^7:1$

$h=\frac{energy}{\frac{c}{\lambda }}$ (Where c is speed of light and h plank's constant and $\lambda$ is wavelength)

$=\frac{M^1{L}^2{T}^{-2}}{\left(\frac{L{T}^{-1}}{L}\right)}$

$=M^1{L}^2{T}^{-1}$

$\Rightarrow h=kg\frac{m^2}{s}$
$h$ (in CGS) $=\left({10}^{3}gm\right)\times ({10}^2{)}^2\frac{c{m}^2}{s}$

$h={10}^{7}gm\frac{c{m}^2}{s}$