The critical angle for light travelling from a transparent medium to air s measured as 340. The refractive index of the medium is

The critical angle is the angle of incidence at which light is just able to pass through the interface between two media and not reflect back. When light travels from a medium with a higher refractive index to a medium with a lower refractive index, it slows down and bends towards the normal. If the angle of incidence is increased, the light will eventually reach a point where it will not be able to escape the higher index medium and will be totally reflected back. This is the critical angle. The formula for the critical angle can be expressed as follows: sin(θc) = n2/n1 Where θc is the critical angle, n1 is the refractive index of the first medium, and n2 is the refractive index of the second medium. In this case, the first medium is the transparent medium and the second medium is air, which has a refractive index of approximately 1. By substituting the value of sin(θc) with the value of 340, and n2 with 1, we can solve for n1. sin(340) = n1/1 n1 = 1/sin(340) The value of n1 calculated using this formula is approximately 1.79, which means that the refractive index of the transparent medium is 1.79.