Even though an electric field `vecE` exerts a force `avecE` on a charged particle yet the electric field of an EM wave does not contribute to the radiation pressure (but transfer energy). Explain.

Explanation

Since electric field of an EM wave is an oscillating field and so is the electric force caused by it on a charged particle. This electric force averaged over an integral number of cycles is zero, since its direction changes every half cycle. Hence, electric field is not responsible for radiation pressure