According to the Cartesian sign convention in ray optics,

$A$ beam of monochromatic light is refracted from vacuum into a medium of refractive index $1.5$. The wavelength of refracted light will be

An opaque sphere of radius $a$ is just immersed in a transparent liquid as shown in the figure. $A$ point source is placed on the vertical diameter of the sphere at a distance $a/2$ from the top of the sphere. One ray originating from the point source after refraction from the air-liquid interface forms a tangent to the sphere. The angle of refraction for that particular ray is $30^{\circ}$. The refractive index of the liquid is:

The refractive index of glass is $3/2$ and the refractive index of water is $4/3$. If the speed of light in glass is $2.00 \times 10^8 \ m/s$,the speed of light in water will be:

Which of the following is a correct relation?

Light enters from air into a given medium at an angle of $45^{\circ}$ with the interface of the air-medium surface. After refraction,the light ray is deviated through an angle of $15^{\circ}$ from its original direction. The refractive index of the medium is