Question

12. The refractive index of a medium ‘x' with respect to a medium ‘y' is 2/3 and the refractive index of medium 'y' with respect to medium 'z' is 4/3. Find the refractive index of medium 'z' with respect to medium ‘x'. If the speed of light in medium ‘x' is 3 x 108 m/s, calculate the speed of light in medium ‘y'. JA 2020




giveaway 50 p


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Answer 1

Answer:

Refractive of med z w.r.t. x is 9/8 and velocity of light in med y is 2 × 10^8 m/s.

Explanation:

We know,

1μ3 = 1μ2 × 2μ3

or simply, n31 = n21 · n32

So,

n(zx) = n(yx) · n(zy)

=> n = 1/n(xy) · 1/n(yz)

{By principle of reversibility.}

=> n = 3/2 × 3/4

=> n = 9/8

Henceforth, refractive index of medium z w.r.t. x is 9/8.

Now, it given that v(x) = 3 × 10^8 m/s

∴ n(x) = 1 {As v(x) = c.}

∵ n(yx) = 2/3

=> n(yx) = n(y)/n(x) = 2/3

=> n(y) = 2/3

=> v(y)/c = 2/3

=> v(y) = 2/3 × 3 × 10^8 m

=> v(y) = 2 × 10^8 m.

P.S. Alphabets enclosed in brackets are meant to be used as subscript.

Answer 2

REFER TO THE ATTACHMENT.