Final answer:
In summary, solar rays are reflected off a parabolic dish and concentrate at its focal point due to parallel solar radiation and equal angles of incidence and reflection, as governed by the law of reflection, increasing the solar dish's efficiency.
Step-by-step explanation:
The relationship between the pair of angles formed by solar radiation reaching a solar dish and the receiver located at the focal point is determined by the principles of geometric optics and reflection. Since the Sun is very distant, the incoming solar rays are nearly parallel by the time they reach Earth. When parallel rays reflect off a parabolic dish, they converge at a single point, the dish's focal point. This is because parabolic mirrors are designed so that incoming parallel rays reflecting off the surface will be directed towards a single focal region where the receiver is placed. The angles of incidence and reflection for each ray are equal, as they reflect off the mirror's surface, according to the law of reflection. This is essential for solar dishes used to generate electricity or heat because it allows for the maximum concentration of solar energy at the receiver, increasing efficiency.