Question

The refractive index of a denser medium with respect to rarer medium is 5/4. The refractive index of rarer medium with respect to denser medium is 1. 5 upon 4 2. root 5 upon 2 3. 2 upon root 5 4. 4 upon 5

Answer 1

Given :

▪ Refractive index of a denser medium wrt rarer medium = 5/4

To Find :

▪ Refractive index of rarer medium wrt denser medium.

Refractive index :

☞ Refractive index of a medium is defined as the factor by which speed of light reduces as compared to the speed of light in vacuum.

☞ Formula : n = c / v

Where,

n = refractive index of medium

c = speed of light in vacuum

v = speed of light in medium

☞ More (less) refractive index implies less (more) speed of light in that medium, which therefore is called denser (rarer) medium.

❇ Refractive index of medium A wrt medium B is given by

n(AB) = n(A) / n(B)

Calculation :

☣ Refractive index of denser medium wrt rarer medium :

→ n(dr) = n(d) / n(r)

→ n(dr) = 5/4

☣ Refractive index of rarer medium wrt denser medium :

→ n(rd) = n(r) / n(d)

→ n(rd) = 1 / n(dr)

→ n(rd) = 1 / (5/4)

→ n(rd) = 4/5

Answer 2

Answer:

YOUR QUESTION :

The refractive index of a denser medium with respect to rarer medium is 5/4. The refractive index of rarer medium with respect to denser medium is 1. 5 upon 4 2. root 5 upon 2 3. 2 upon root 5 4. 4 upon 5.

YOUR ANSWER :

Given :

• Refractive index of a denser medium wrt rarer medium = 5/4

To Find :

• Refractive index of rarer medium wrt denser medium.

Refractive index :

✔Formula : n = c / v

n = refractive index of medium

c = speed of light in vacuum

v = speed of light in medium

✔ Refractive index of medium A wrt medium B is given by

• n(AB) = n(A) / n(B)

Calculation :

✔ Refractive index of denser medium wrt rarer medium :

=> n(dr) = n(d) / n(r)

=> n(dr) = 5/4.

✔ Refractive index of rarer medium wrt denser medium :

=> n(rd) = n(r) / n(d)

=> n(rd) = 1 / n(dr)

=> n(rd) = 1 / (5/4)

=> n(rd) = 4/5.