The linear velocity \( v \) is given by: \[ v = r \cdot \omega, \] where \( r \) is the radius and \( \omega \) is the angular velocity. 
Given: \[ \text{Diameter} = 20 \, \text{cm} \Rightarrow r = \frac{20}{2} = 10 \, \text{cm} = 0.1 \, \text{m}. \] 
The angular velocity \( \omega \) is: \[ \omega = 2\pi f, \quad f = \frac{\text{rpm}}{60} = \frac{600}{60} = 10 \, \text{rps}. \] 
Substituting values: \[ v = 0.1 \cdot (2\pi \cdot 10) = 0.1 \cdot 20\pi \approx 6.28 \, \text{m/s}. \]
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). 
Assertion (A): Electromagnetic waves carry energy but not momentum. 
Reason (R): Mass of a photon is zero. In the light of the above statements.
choose the most appropriate answer from the options given below:
The dimension of $ \sqrt{\frac{\mu_0}{\epsilon_0}} $ is equal to that of: (Where $ \mu_0 $ is the vacuum permeability and $ \epsilon_0 $ is the vacuum permittivity)