[" A beam of monochromatic blue "],[" light of wavelength "4200 AA" in air "],[" travels in water "(n=4/3)" .Its "],[" wavelength in water is "]

A beam of monochromatic blue light of wavelength 4200 Å in air travels in water (mu = 4//3) . It's wavelengths in water will be

A beam of monochromatic blue light of wavelength 4200 Å in air travels in water of refractive index 4/3. Its wavelength in water will be:

A beam of menochromatic blue light of wavelength 4200 Ål in air travels in water of refractive index 4/3. its wavelength in water will be

A beam of menochromatic blue light of wavelength 4200 Ål in air travels in water of refractive index 4/3. its wavelength in water will be

A beam of menochromatic blue light of wavelength 4200 Ål in air travels in water of refractive index 4/3. its wavelength in water will be

A beam of monochromatic blue light of wavelength 4200 Å in air , travels in water of refractive index (4)/(3) . What is the its wavelength in water ?