The ratio of amplitude of magnetic field to the amplitude of electric field for an electromagnetic wave propagating in vacumm is equal to

Options

A. the speed of light in vacuum
B. reciprocal of speed of light in vacuum
C. the ratio of magnetic permeability to the electric susceptibility of vacuum
D. unity

Answer

B

Explanation

The average energy stored in the electric field and magnetic field respectively are
`U_(E )=(1)/(2)epsilon_(0)E^(2) and U_(B)=(1)/(2)(B^(2))/(mu_(0))`,
According to conservation of energy `U_(E)=U_(B)`
`epsilon_(0)mu_(0)=(B^(2))/(E^(2))rArr (B)/(E)=sqrt(epsilon_(0)mu_(0))=(1)/(C )`