When the incident light itself is polarized with electric field vector in the plane of incidence, then if the angle of incidence is θp, there is no
Reflected light
The component of light beam that vibrates perpendicular to the reflecting surface is reflected less as compared to the component parallel to the surface. So, if the incident light itself is polarized with electric field vector in the plane of incidence, there is no reflected light when the angle of incidence is θp.