Question

The magnetic field of a plane electromagnetic wave travelling in +ve z-direction is described by ______.

Options

• `"B"_"y"= "B"_0 sin ("kz")`

• `"B"_"y" = "B"_0 sin ("kz" + omega"t")`

• `"B"_"y" = "B"_0 sin ("kz" - omega"t")`

• `"B"_"y" = "B"_0 sin (2"kz")`

Answer 1

The magnetic field of a plane electromagnetic wave travelling in +ve z-direction is described by `underline("B"_"y" = "B"_0 sin ("kz" - omega"t"))`.

Explanation:

Both electric and magnetic fields are perpendicular to the wave's propagation direction in an em-wave. As a result, `"B"_"y" = "B"_0sin ("kz" - omega"t")`, where k is the propagation constant and is the angular velocity.