11) A glass plate has a thickness of 4.0 mm. A light beam is incident from air towards the glass plate at an angle of incidence of 60 °. How long does it take for the light beam to pass the glass plate? The refractive index of the glass is 1.55.

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.