For a colour of light the wavelength for air is 6000 mathringA and in water the wavelength is4500 mathringA. Then the speed of light in water will be

Question

For a colour of light the wavelength for air is 6000 mathringA and in water the wavelength is4500 mathringA. Then the speed of light in water will be (A) 5 × 1014 m / s (B) 2.25 × 108 m / s (C) 4.0 × 108 m / s (D) zero

Tardigrade Admin · Accepted Answer

We know that v propto λ ⇒ (v1/v2)=(λ1/λ2) ⇒ v2=(v1/λ1) × λ2 =3 × 108 × (4500/6000)=2.25 × 108 m / s

Q. For a colour of light the wavelength for air is $6000 \overset{˚}{A}$ and in water the wavelength is $4500 \overset{˚}{A}$ . Then the speed of light in water will be

$5 \times 1 0^{14} m / s$

$2.25 \times 1 0^{8} m / s$

$4.0 \times 1 0^{8} m / s$

zero

We know that $v \propto λ$
$\Rightarrow \frac{v _{1}}{v _{2}} = \frac{λ _{1}}{λ _{2}}$
$\Rightarrow v_{2} = \frac{v _{1}}{λ _{1}} \times λ_{2}$
$= 3 \times 1 0^{8} \times \frac{4500}{6000} = 2.25 \times 1 0^{8} m / s$

Q. For a colour of light the wavelength for air is 6000A˚ and in water the wavelength is4500A˚. Then the speed of light in water will be

5×1014m/s

2.25×108m/s

4.0×108m/s