please solve 31 There is an Electric field of magnitude 2Vm

please solve 3.1

There is an Electric field of magnitude 2[V/m] at an angle of 46 degree from the boundary as shown Just below the boundary in the glass the electric field 3 [V/m] what is the angle theta in the glass?

Solution

As tangential component of electric field is continuous at interface, hence

3*sin(theta)= 2*sin(46)

Sin(theta)=0.479

theta=28 degree