question_answer

Four students P, Q, R and S traced the path of a ray of light passing through a glass slab for an angle of incidence \[\mathbf{4}{{\mathbf{0}}^{\mathbf{o}}}\] and measured the angle of refraction. The values as measured them were \[\mathbf{1}{{\mathbf{8}}^{\mathbf{o}}}\mathbf{;}\,\mathbf{2}{{\mathbf{2}}^{\mathbf{o}}}\mathbf{;}\,\mathbf{2}{{\mathbf{5}}^{\mathbf{o}}}\] and \[\mathbf{3}{{\mathbf{0}}^{\mathbf{o}}}\] respectively. The student who has performed the experiment methodically is

(a) P                                                     (b) Q

(c) R                                                     (d) S

Answer:

(c) R