Snell's Law of Refraction

Q. Use Snell's law to find the refractive index of an interface when the angle of incidence is ${60}^{\circ }$ and the angle of refraction is ${30}^{\circ }$.

1. $\sqrt{3}$
2. $3$
3. $\sqrt{2}$
4. $2$

Q.

Find out the angle of refraction when a light travels from medium A to medium B.

Speed of light in A $=2\times {10}^{8}m/s$
Speed of light in B $=3\times {10}^{8}m/s$

1. $si{n}^{-1}\left(\frac{4}{3}\right)$

2. $si{n}^{-1}\left(\frac{1}{2}\right)$

3. $si{n}^{-1}\left(\frac{3}{4}\right)$

4. $si{n}^{-1}\left(\frac{1}{3}\right)$

Q.

Light is going from some denser medium to air The refractive index of the medium is 1.7. Calculate the angle of incidence, such that if it is further increased, Total internal reflection will occur at medium I.

1. $si{n}^{-1}\left(\frac{1}{\sqrt{2}}\right)$
2. $si{n}^{-1}\left(\frac{1}{\sqrt{5}}\right)$
3. $si{n}^{-1}\left(\frac{1}{\sqrt{3}}\right)$
4. Such an angle of incidence can't be calculated.

Q. The refractive index of the core of an optical fiber is ${\mu }_2$ and that of the cladding is ${\mu }_1$. The angle of incidence on the face of the core so that the light ray just undergoes total internal reflection at the cladding is

1. $si{n}^{-1}\left(\sqrt{{\mu }_2^2-{\mu }_1^2}\right)$
2. $si{n}^{-1}\left(\sqrt{{\mu }_1^2-{\mu }_2^2}\right)$
3. $si{n}^{-1}\left(\frac{{\mu }_1}{{\mu }_2}\right)$
4. $si{n}^{-1}({\mu }_2-{\mu }_1)$

Q.

Light is going from some denser medium to air. The refractive index of the medium is 1.7.Calculate the angle of incidence, such that if it is further increased, total internal reflection will occur.

1. $si{n}^{-1}\left(\frac{1}{\sqrt{2}}\right)$

2. $si{n}^{-1}\left(\frac{1}{\sqrt{5}}\right)$

3. $si{n}^{-1}\left(\frac{1}{\sqrt{3}}\right)$

4. Such an angle of incidence can't be calculated.

Q. For a light ray passing from air to water, according to Snell's law:
($n$ represents refractive index of the medium, ${\theta }_{air}$ is the angle of incidence and ${\theta }_{water}$ is the angle of refraction)

1. $n_{air}$ $Sin{\theta }_{air}$ = $n_{water}$ $Sin{\theta }_{water}$
2. $n_{air}$ $Sin{\theta }_{water}$ = $n_{water}$ $Sin{\theta }_{air}$
3. $n_{air}$ $Sin{\theta }_{air}$ $n_{water}$ $Sin{\theta }_{water}$ = 1
4. $n_{air}$ $n_{water}$ = $Sin{\theta }_{water}$ $Sin{\theta }_{air}$

Q. According to Snells law, the factor that remains constant for a given pair of media and different angles of incidence and refraction is:

1. Wavelength
2. Speed
3. Distance
4. Refractive index

Q. What would be the refractive index of the liquid in the given figure?

1. $\sqrt{\frac{2}{3}}$
2. $\sqrt{\frac{3}{4}}$
3. $\sqrt{\frac{3}{2}}$
4. $\sqrt{\frac{4}{3}}$