
The relationship between the amplitude of the magnetic field (B0) and the amplitude of the electric field (E0) in an electromagnetic wave propagating in vacuum can be described by the equation:
BE=1c
Where,
This shows that the ratio of the amplitude of the magnetic field to the amplitude of the electric field in an electromagnetic wave is the reciprocal of the speed of light.
Therefore, the correct option is: Reciprocal of speed of light in vacuum

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)
The unit of $ \sqrt{\frac{2I}{\epsilon_0 c}} $ is: (Where $ I $ is the intensity of an electromagnetic wave, and $ c $ is the speed of light)
A solid cylinder of mass 2 kg and radius 0.2 m is rotating about its own axis without friction with angular velocity 5 rad/s. A particle of mass 1 kg moving with a velocity of 5 m/s strikes the cylinder and sticks to it as shown in figure. 
The angular velocity of the system after the particle sticks to it will be: