Physics - Geometrical Optics Question with Solution | TestHub

According to Snell's law Refractive index, $\mu =\frac{\sin i}{\sin r}$ Given $i=2r$ $\therefore$ $$\mu =\frac{\sin 2r}{\sin r}$$ or $\mu =\frac{2\sin r\cos r}{\sin r}$ or ${\cos }^{-1}\frac{\mu }{2}=r$ $$i=2{\cos }^{-1}\frac{\mu }{2}$$