In a Young's double slit experiment, d=0.5 mm and D=100 cm It is found that 9 text th bright fringe is at a distance of 7.5 mm from the second dark fringe of fringe pattern. The wavelength of light used is (in mathringA)

Question

In a Young's double slit experiment, d=0.5 mm and D=100 cm It is found that 9 text th bright fringe is at a distance of 7.5 mm from the second dark fringe of fringe pattern. The wavelength of light used is (in mathringA) (A) (2500/7) (B) 2500 (C) 5000 (D) (5000/7)

Tardigrade Admin · Accepted Answer

For bright fringes, x=(n λ D/d) where n=0,1,2,3, dots For dark fringes, x=((2 n-1) λ D/2 d) where n=1,2,3, dots As per question, (9 λ D/d)-(3 λ D/2 d)=7.5 × 10-3 m or (15 λ D/2 d)=7.5 × 10-3 m or λ=(2 × 7.5 × 10-3 × d/15 D) Substituting the given values, we get λ=(2 × 7.5 × 10-3 m × 0.5 × 10-3 m /15 × 1 m ) =0.5 × 10-6 m =5000 mathringA

Q. In a Young's double slit experiment, $d = 0.5 mm$ and $D = 100 c m$ It is found that $9^{th}$ bright fringe is at a distance of $7.5 mm$ from the second dark fringe of fringe pattern. The wavelength of light used is (in $\overset{˚}{A})$

$\frac{2500}{7}$

2500

5000

$\frac{5000}{7}$

Q. In a Young's double slit experiment, d=0.5mm and D=100cm It is found that 9th bright fringe is at a distance of 7.5mm from the second dark fringe of fringe pattern. The wavelength of light used is (in A˚)

72500​

2500

5000

75000​

Q. In a Young's double slit experiment, $d = 0.5 mm$ and $D = 100 c m$ It is found that $9^{th}$ bright fringe is at a distance of $7.5 mm$ from the second dark fringe of fringe pattern. The wavelength of light used is (in $\overset{˚}{A})$

$\frac{2500}{7}$

$\frac{5000}{7}$