The dimensional formula of angular velocity is

The dimensional formula of a physical quantity represented by $\frac{e^2}{4 \pi \varepsilon_0 \hbar}$ is (where $e$ is the charge of an electron,$\varepsilon_0$ is the permittivity of free space,and $\hbar$ is the reduced Planck's constant). Note: The expression $\frac{e^2}{4 \pi \varepsilon_0 \hbar}$ is equivalent to the fine-structure constant $\alpha$ multiplied by the speed of light $c$.

Write the magnitude and dimensional formula of $\frac{1}{\sqrt{\mu_0 \epsilon_0}}$.

The dimensions of pressure are

Consider that $\sigma_s$, $k_B$, and $b$ represent the Stefan-Boltzmann constant, Boltzmann constant, and Wien's displacement law constant, respectively. The dimension of $\sigma_s k_B^{-1}$ is:

The unit of Planck's constant is