Answer:
490 nm
Explanation:
Wave length: This is the distance of a complete cycle covered by a wave.
The expression for frequency, wave length and speed is given as,
c = λf.................. Equation 1
Where c = speed of light in water, λ = wave length of light, f = frequency of light.
Also,
n = v/c............. Equation 2
Where n = refractive index of water, v = speed of sound in air.
Making c the subject of the equation,
c = v/n.............. Equation 3
Substitute equation 3 into equation 2
v/n = λf
make λ the subject of the equation
λ = v/nf............... Equation 4
Given: f = 4.6 × 10¹⁴ Hz
Constant: n = 1.33, v = 3.0×10⁸ m/s.
Substitute into equation 4
λ = 3.0×10⁸ /(1.33×4.6 × 10¹⁴ )
λ = 0.49×10⁻⁶ m
λ = 490 nm.
Hence the right option is 490 nm
