Question

Gravitational constant (G), Rydberg constant (R) and speed of light (C) are three constants. Which of the following has dimension of time?

• A. $RC$
• B. $R^{-1}{C}^{-1}$
• C. $G^2{R}^{-1}{C}^{-1}$
• D. $G{R}^{-1}{C}^2$

Answer 1

The correct option is B $R^{-1}{C}^{-1}$

Rydberg constant $=1.09\times {10}^7{\text{m}}^{-1}$ $R=\left[{\text{L}}^{-1}\right]$
$C=\left[{\text{LT}}^{-1}\right]$
Time = $\frac{\text{distance}}{\text{speed}}=\frac{\frac{1}{R}}{C}=\frac{1}{RC}$