(a)[1]
State the name used for the dashed lines in Fig. 6.1.
(b(i))[2]
State what is meant by the term critical angle.
(b(ii))[3]
On Fig. 6.1, show the path of each ray after it reaches the water-air boundary.
Physics 0625 · IGCSE · Light
Light — practice question
A diver is underwater and is using a torch that emits red light. Fig. 6.1 shows three rays of red light from the torch. In Fig. 6.1, dashed lines are drawn at the boundary and the angles are labelled 20^{\circ}, 40^{\circ} and 60^{\circ}; the regions are labelled air and water.