Reflection on science experiment

During the experiment, 2P12, we experimented on the critical angle of an object and learned about total internal reflection. During this experiment, firstly, we had to prepare a laser unit, protractor, ruler, screen, rectangle block and semi-circle block. Next, we had to pinpoint the laser at the semi-circular block to create a small angle of incidence at the center of the semi-circular block. After which, gradually increase the angle until the laser emerges along the edge of the semi-circular block. When the laser reaches that state, measure the angle of incidence. That is the critical angle. If we continue to increase the angle of incidence, the laser will reflect within the semi-circular block instead of refracting out of the block. This is called total internal reflection. However, if we make the angle of incidence 0 degree, the laser will not refract and just exit the block in a straight line. Therefore, from this experiment, I could conclude that, the critical angle is the angle where the light ray emerges along the edge of the block and not refract nor reflect. Also, total internal reflection only occur when the angle of incidence is larger than the critical angle. Lastly, if the angle of incidence is 0 degrees, the light ray will go straight and exit the semi-circular block in a straight line. That is what I learned in this experiment.