Question

The dimensional formula for Rydberg constant is

• A. $\left[ M ^{0} LT ^{-1}\right]$
• B. $\left[ M ^{0} L ^{-1} T ^{0}\right]$
• C. $\left[ M ^{0} L ^{0} T ^{0}\right]$
• D. $[MLT]$

Answer 1

Answer: (B)

$\frac{1}{\lambda}=R Z^{2}\left[\frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}}\right]$
$Z$ is atomic number, $n_{1}$ and $n_{2}$ are the principal quantum numbers,
Hence $[R]=\left[\frac{1}{\lambda}\right]= L ^{-1} ; \Rightarrow [R]=\left[ M ^{0} L ^{-1} T ^{0}\right]$