Question

The frequency of a light wave in a material is \( 2 \times 10^{14} \,\text{Hz} \) and wavelength is \( 5000 \,\text{\AA} \). The refractive index of material is:

• A. 1.50
• B. 3.00
• C. 1.33
• D. 1.40

Hint:

Light slows down when entering a medium with a higher refractive index.

Answer 1

The Correct Option is B

Step 1: Concept
Refractive index $n = \frac{c}{v}$, where $v = \nu \lambda$.
Step 2: Analysis
$v = (2 \times 10^{14} \text{ Hz}) \times (5000 \times 10^{-10} \text{ m}) = 10^{8} \text{ m/s}$.
$n = \frac{3 \times 10^{8}}{1 \times 10^{8}} = 3$.
Step 3: Conclusion
The refractive index of the material is 3.00.
Final Answer: (B)