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Can reflection result in plane polarised light if the light is incident on the interface from the side with higher refractive index ? |
Answer» Solution : Here, incident ray is in denser MEDIUM (medium-2) and REFRACTED ray is in rarer medium (medium-1). Hence, according to Brewster.s law, `tantheta_(P)=(n_(1))/(n_(2))""......(1)` ( Where `theta_(P)=` POLARISATION angle or Brewster angle) Here if critical angle of denser medium w.r.t. rarer medium is C then according to Snell.s law, `n_(2)sinC=n_(1)sin90^(@)` `:.sinC=(n_(1))/(n_(2))""......(2)` From equation(1) and (2), `tantheta_(P)=sinC` `:.(sintheta_(P))/(costheta_(P))=sinC` `:.sintheta_(P)=(costheta_(P))sinC` But here `0ltcostheta_(P)lt1` `impliessintheta_(P)ltsinC` `impliessintheta_(P)ltsinC` For a ray of light made incident on the surface of rarer medium with polarisation angle, SATISFYING above condition, reflected light will be completely plane polarised. |
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