a radio antenna broadcasts a 1.0 MHz radio wav e with 21 kW of power. Assume that the radiation is emitted uniformly in all directions. What

Question

a radio antenna broadcasts a 1.0 MHz radio wav e with 21 kW of power. Assume that the radiation is emitted uniformly in all directions. What is the waves intensity 25 km from the antenna

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Philomena 3 months 2021-08-12T07:53:59+00:00 1 Answers 2 views 0

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    2021-08-12T07:55:43+00:00

    Answer:

    I=2.67\times 10^{-6}\ W/m

    Explanation:

    Given that,

    Frequency of a radio antenna is 1 MHz

    Power, P = 21 kW

    We need to find the the waves intensity 25 km from the antenna
    . The object emits intenisty evenly in all direction. It can be given by :

    I=\dfrac{P}{4\pi r^2}\\\\I=\dfrac{21\times 10^3}{4\pi (25000)^2}\\\\I=2.67\times 10^{-6}\ W/m

    So, the wave intensity 25 km from the antenna is 2.67\times 10^{-6}\ W/m.

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