Question

If 'a' is the thickness of the glass slab and 'b' is the vertical shift of an object through it, then refractive index of the glass slab is

• A. \(\frac{a}{a+b}\)
• B. \(\frac{a}{a-b}\)
• C. \(\frac{a-b}{a}\)
• D. \(\frac{a-b}{b}\)

Answer 1

The Correct Option is B

When an object is viewed through a glass slab, it appears raised due to the refraction of light. The formula to calculate the refractive index \( \mu \) of the glass is: \[ \mu = \frac{\text{Real thickness}}{\text{Apparent thickness}} = \frac{a}{a - b} \] Here, - \( a \) is the real thickness of the glass slab - \( b \) is the vertical shift (apparent reduction in thickness due to refraction).

The correct option is (B): \(\frac{a}{a-b}\)