Assertion (A): Electromagnetic waves exert pr | vedclass

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(B) Electromagnetic waves $(EMW)$ carry both energy and momentum. When these waves strike a surface,they transfer momentum to the surface,which result

Vedclass · Accepted Answer

Both $A$ and $R$ are true but $R$ is not a correct explanation for $A$.

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(B) Electromagnetic waves $(EMW)$ carry both energy and momentum. When these waves strike a surface,they transfer momentum to the surface,which results in the exertion of radiation pressure.For a perfectly reflecting surface,the radiation pressure is $p = 2I/c$,where $I$ is the intensity and $c$ is the speed of light.For a perfectly absorbing surface,the radiation pressure is $p = I/c$.Thus,Assertion $(A)$ is true.Reason $(R)$ states that they exert pressure because they carry energy. While it is true that $EMW$ carry energy,the pressure is exerted specifically because they carry momentum $(p = E/c)$. Therefore,the fact that they carry energy is not the direct or complete explanation for the existence of radiation pressure.Hence,both $A$ and $R$ are true,but $R$ is not the correct explanation for $A$.

Assertion $(A)$: Electromagnetic waves exert pressure,called radiation pressure.
Reason $(R)$: This is because they carry energy.

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Assertion $(A)$: Electromagnetic waves exert pressure,called radiation pressure.Reason $(R)$: This is because they carry energy.