# The electric field of a plane polarized electromagnetic wave in free space at time t=0 is given by an expression (x, y) = 10 cos [(6x+8z)] The magnetic field  (x, z, t) is given by :(c is the velocity of light) (a) = (6+8)cos [(6x−8z+10ct)] (b) (6−8)cos[(6x+8z−10ct)] (c) (6+8)cos[(6x+8z−10ct)] (d) (6−8)cos[(6x+8z+10ct)]

## Question ID - 50259 :- The electric field of a plane polarized electromagnetic wave in free space at time t=0 is given by an expression (x, y) = 10 cos [(6x+8z)] The magnetic field  (x, z, t) is given by :(c is the velocity of light) (a) = (6+8)cos [(6x−8z+10ct)] (b) (6−8)cos[(6x+8z−10ct)] (c) (6+8)cos[(6x+8z−10ct)] (d) (6−8)cos[(6x+8z+10ct)]

3537

Answer Key : (b) -

=10 cos [(6+8). (x+z)]

=10 cos []

=6+8; direction of waves travel.

i.e. direction of ‘c’.

∴ Direction of  will be along

×=

Mag. of  will be along ×=

Mag. of  ==

==

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