In Fresnel's biprism expt., a mica sheet of refractive index 1.5 and thickness 6 × 10-6 m is placed in the path of one of interfering beams as a result of which the central fringe gets shifted through 5 fringe widths. The wavelength of light used is

Question

In Fresnel's biprism expt., a mica sheet of refractive index 1.5 and thickness 6 × 10-6 m is placed in the path of one of interfering beams as a result of which the central fringe gets shifted through 5 fringe widths. The wavelength of light used is (A) 6000 mathringA (B) 8000 mathringA (C) 4000 mathringA (D) -2000 mathringA

Tardigrade Admin · Accepted Answer

Where n is equivalent number of fringe by which the centre fringe is shifted due to mica sheet λ=((μ-1) t/n)=((1.5-1) 6 × 10-6/5)=6000 mathringA

Q. In Fresnel's biprism expt., a mica sheet of refractive index $1.5$ and thickness $6 \times 1 0^{- 6} m$ is placed in the path of one of interfering beams as a result of which the central fringe gets shifted through $5$ fringe widths. The wavelength of light used is

$6000 \overset{˚}{A}$

$8000 \overset{˚}{A}$

$4000 \overset{˚}{A}$

$- 2000 \overset{˚}{A}$

Where $n$ is equivalent number of fringe by which the centre fringe is shifted due to mica sheet
$λ = \frac{( μ - 1 ) t}{n} = \frac{( 1.5 - 1 ) 6 \times 1 0 ^{- 6}}{5} = 6000 \overset{˚}{A}$

Q. In Fresnel's biprism expt., a mica sheet of refractive index 1.5 and thickness 6×10−6m is placed in the path of one of interfering beams as a result of which the central fringe gets shifted through 5 fringe widths. The wavelength of light used is

6000A˚

8000A˚

4000A˚

−2000A˚