Question

A beam of monochromatic blue light of wavelength $4200A^{\circ }$ in air travels in water $\mu =\frac{4}{3}$. Its wavelength in water will be

• A. $2800A^{\circ }$
• B. $5600A^{\circ }$
• C. $3150A^{\circ }$
• D. $4000A^{\circ }$

Answer 1

The correct option is C $3150A^{\circ }$

$\mu \infty \frac{1}{\lambda }\Rightarrow \frac{{\mu }_1}{{\mu }_2}=\frac{{\lambda }_2}{{\lambda }_1}\Rightarrow \frac{1}{\frac{4}{3}}=\frac{{\lambda }_2}{4200}\Rightarrow {\lambda }_2=3150A^{\circ }$