A plane electromagnetic wave travels in free space along X-direction. If the value of `vecB` (in tesla) at a particular point in space and time is `1.2 xx 10^(-8) hatk`. The value of `vecE` (in `Vm^(-1)`) at that point is

Options

A. `1.2hatj`
B. `3.6hatk`
C. `1.2hatk`
D. `3.6hatj`

Answer

D

Explanation

Here, `vecB=1.2xx10^(-8)hatkT`
The magnitude of `vecE`is
`E=Bc=(1.2xx10^(-8)T)(3xx10^(8)ms^(-1))=3.6Vm^(-1)`
`vecB` is along Z - direction and the wave propagates along x - direction. Therefore `vecE` should be in a direction perpendicular to both x and z axes. Using vector algebra `vecExxv ecB` should be along x - direction.
Since `(+hatj)xx(+hatk)=hati, vecE` is along the y - direction.
Thus, `vecE=3.6hatjVm^(-1)`.