For emission line of atomic hydrogen from ni = 8 to nf = the plot of wave number ($\vec{v}$) against $\left({1\over n^2}\right)$ will be (The Rydberg constant, RH is in wave number unit).
(1) Linear with slope - RH
(2) Linear with intercept - RH
(3) Non linear
(4) Linear with sslope RH