The log-log graph between the energy E of an electron and its de-Broglie wavelength λ will be

λ=h2mE=h2m.1E.logλ=logh2m+log1E⇒logλ=logh2m−12logElogλ=−12logE+logh2mThis  is  the  equation  of  straight line  having slope  −1/2  and  positive  intercept   on  logλ  axis & logE axis