Even though an electric field E exerts a force qE on a charged particle yet the electric field of an EM wave does not contribute to the radiation pressure (but transfers energy). Explain.
Hint: The electric field of an EM wave is a variable electric field.
Step 1: Find the average electric force on a charged particle.
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 zero, since its direction changes every half cycle.
Hence, electric field is not responsible for radiation pressure.
