Physics 0625 · IGCSE · Light

Light — practice question

Fig. 8.1 illustrates a ray of red light striking one face of a glass prism in air. For red light, glass has refractive index $n_R$.
(a(i))[2]

Calculate $n_R$.

(a(ii))[1]

On Fig. 8.1, sketch a line to show the route taken by the red light as it comes out of the glass prism. Mark this path R.

(a(iii))[1]

Explain why refractive index has no unit.

(b(i))[1]

A ray of violet light travels into the prism along the same route as the ray of red light. On Fig. 8.1, sketch a line to show the path of the violet light through the prism and as it emerges into the air. Label this path V.

(b(ii))[3]

State how the speed of light in glass varies with its frequency. Explain how this is shown by the dispersion of white light in the prism.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: $n=\dfrac{\sin i}{\sin r}$

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