Direction of the first secondary maximum in the Fraunhofer diffraction pattern at a single slit is given by ( a is the width of the slit)

Question

Direction of the first secondary maximum in the Fraunhofer diffraction pattern at a single slit is given by ( a is the width of the slit) (A) a sin θ=(λ/2) (B) a cos θ=(3 λ/2) (C) a sin θ=λ (D) a sin θ=(3 λ/2)

Tardigrade Admin · Accepted Answer

For n text th secondary maxima path difference d sin θ=(2 n+1) (λ/2) ⇒ a sin θ=(3 λ/2)

Q. Direction of the first secondary maximum in the Fraunhofer diffraction pattern at a single slit is given by ( $a$ is the width of the slit)

$a sin θ = \frac{λ}{2}$

$a cos θ = \frac{3 λ}{2}$

$a sin θ = λ$

$a sin θ = \frac{3 λ}{2}$

For $n^{th}$ secondary maxima path difference
$d sin θ = (2 n + 1) \frac{λ}{2}$
$\Rightarrow a sin θ = \frac{3 λ}{2}$

Q. Direction of the first secondary maximum in the Fraunhofer diffraction pattern at a single slit is given by ( a is the width of the slit)

asinθ=2λ​

acosθ=23λ​

asinθ=λ

asinθ=23λ​