Question

Green light with a wavelength of 550 (nm) and a speed of 3 X 10^8 (m/s) in Air travels through Glass (n = 1.5). Its speed in glass in (m/s) is : a. 1.5 X 10^8 b. 3 X 10^8 c. 4.5 X10^8 d. 6 X 10^8

Answer 1

Answer: The speed of light in glass is
`2* 10^8m/s`

Step-by-step explanation:

To calculate the velocity of light in a medium for given refractive index, we use the equation:

`\eta=(c)/(v)`

where,

`\eta` = refractive index of glass = 1.5

c = speed of light in air =
`3* 10^8m/s`

v = speed of light in medium = ?

Putting values in above equation, we get:

`1.5=(3* 10^8m/s)/(v)\\\\v=2* 10^8m/s`

Hence, the speed of light in glass is
`2* 10^8m/s`