What is the maximum wavelength of line of Balmer series of hydrogen spectrum `(R=1.09xx10^(7)m^(-1))`-

Options

A. 400nm
B. 660nm
C. 486nm
D. 434nm

Answer

B

Explanation

For maximum wavelength in the Balmer series, `n_(2)=3 and n_(1)=2`
`therefore (1)/(lamda)=1.09xx10^7 xx1^(2)((1)/(2^(2))-(1)/(3^(2)))`
or `(1)/(lamda)=1.09xx10^(7)xx1((1)/(4)-(1)/(9))=1.09xx10^(7)xx1((5)/(36))`
or `lamda=(36)/(5xx1.09xx10^(7))m6.60xx10^(-7)m=660` nm