Target Exam

CUET

Subject

Physics

Chapter

Electromagnetic Waves

Question:

When white light consisting of wavelengths ranging from 400 nm to 700 nm passes through water (μ = 4/3), then the wavelength range in water will be:

Options:

300 nm - 525 nm

500 nm - 700 nm

700 nm - 850 nm

450 Å - 750 Å

Correct Answer:

300 nm - 525 nm

Explanation:

The correct answer is Option (1) → 300 nm - 525 nm

Wavelength in a medium: $\lambda_\text{medium} = \frac{\lambda_\text{vacuum}}{\mu}$

Given $\mu = \frac{4}{3}$, white light range: 400 nm to 700 nm

In water:

Minimum wavelength: $\lambda_\text{min} = \frac{400}{4/3} = 300\ \text{nm}$

Maximum wavelength: $\lambda_\text{max} = \frac{700}{4/3} = 525\ \text{nm}$

Final Answer: Wavelength range in water = 300 nm to 525 nm