Question

Air has refractive index 1.0003. The thickness of air column which will have one more wavelength of yellow light (600 nm) than in the same thickness of vacuum is:

• A. 2 m
• B. 2 cm
• C. 2 mm
• D. 0.2mm

Answer 1

Answer: (C)

2 mm

Answer 2

$\frac{x}{\lambda_a}=\frac{x}{\lambda_v}+1\,Also\,\lambda_a=\frac{\lambda_v}{n}=\frac{600}{1.0003}nm$This gives x = 2 mm.