Read the paragraph and the figure carefully and answer the questions. The figure shows a constant deviation prism ABCD. The incident ray is PQ and the emergent ray is ST. Although it is made up of one piece of glass, it is equivalent to two 30∘−60∘−90∘ prisms and one 45∘−45−90∘ prism. The angle θ1 is the angle of incidence on face AB. The path of the ray inside the prism is indicated in the figure. For this prism, μ=2 sin θ1 The ratio of θ1/θ2 is