In a single slit diffraction pattern, the first minima for a wavelength `lamda_(1)=6000` Å coincides with the first maxima for a wavelength `lamda_(2)`. Then the value of `lamda_(2)` is

Options

A. 8000 Å
B. 4000 Å
C. 5500 Å
D. 3500 Å

Answer

B

Explanation

`asintheta_(1)=nlamda_(1)" "therefore sintheta_(1)=(lamda_(1))/(a)`
`a sintheta_(2)=(3lamda_(2))/(2)" "therefore sintheta_(2)=(3lamda_(2))/(2a)`
`because theta_(1)=theta_(2)" "therefore (lamda_(1))/(a)=(3lamda_(2))/(2a)`
`therefore lamda_(2)=(2)/(3)lamda_(1)=(2)/(3)xx6000=4000` Å