An electromagnetic wave of frequency 45 MHz travels in free space along X -axis . At some point and at some instant the electric field has a maximum value of 750 `NC^(-1)` along Y -axis . The magnetic field at this position and time is

Options

A. `2.5 xx 10^(-6) hatj`
B. `5xx10^(-6) hatk T `
C. `2.5 xx 10^(-6) hatk T `
D. `2.5 xx 10^(-6) hati T`

Answer

C

Explanation

Relation between electric and magnetic field in electromagnetic wav
`B = (E )/( C ) `
E = 750N /C
Speed of light
`c= 3xx 10^(8) `m/s
`B= (750)/(3xx10^(8))`
`B= 2.5xx10^(-6)T `
As B must be perpendicular to both c and E i.e it is along Z - axis .
`B=2.5 xx 10^(-6) hatkT`