Question

calculate the speed of light in a medium whose refractive index is 2.4 given speed of the light in air is 3*10^8 m/s
​

Answer 1

Answer:

2×10 8 ms-1

Explanation:

According to Snell's Law:

sin r

sin i

=

n

1

n

2

=

v

2

v

1

and Refractive Index for air is ≈1

Substituting,

1

1.5

=

v

2

3×10

8

Therefore, v

2

=

1.5

3×10

8

=2×10

8

m/s

Answer 2

Answer:

Explanation:

Correct option is

D

1.25

The refraction index, n, of a transparent medium is defined as the ratio of speed of light in vacuum to the speed of light in that medium.  The formula is n=  

v

c

​

.

where the speed of light c=3×10  

8

m/s and v is the speed of light in the desired medium which is given as v=2.4×10  

8

m/s.

Therefore, n=  

2.4×10  

8

m/s

3×10  

8

m/s

​

=1.25.

Hence, the refractive index of the transparent medium is 1.25.