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The electric field in an electromagnetic wave is given by E = 56.5 sin ω ( t − x / c ) N C − 1 .  Find the intensity of the wave if it is propagating along x-axis in the free space.

(Given ∈ 0 = 8 . 8 5 × 1 0 − 1 2 C 2 N − 1 m − 2 )

Option 1 -

5.65 Wm-2

Option 2 -

4.24 Wm-2

Option 3 -

1.9 * 10-7 Wm-2 

Option 4 -

56.5 Wm-2

0 2 Views | Posted 2 months ago
Asked by Shiksha User

  • 1 Answer

  • V

    Answered by

    Vishal Baghel | Contributor-Level 10

    2 months ago
    Correct Option - 2


    Detailed Solution:

    E = 5 6 . 5 s i n ( w ( t − x c ) ) N / c

    E 0 = 5 6 . 5

    ε 0 = 8 . 8 5 × 1 0 − 1 2

    C = 3 × 108

    l = 1 2 ε 0 E 0 2 C

    = 1 2 × 8 . 8 5 × 1 0 − 1 2 × ( 5 6 . 5 ) 2 × 3 × 1 0 8

    = 4 2 3 7 7 . 1 1 × 1 0 − 4

    l = 4 . 2 4 w m − 2

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