Q: The graph of $\large ln \frac{R}{R_o} \; v/s \; lnA $ (R: radius of nucleus, A: mass number) is

(a) a straight line

(b) a parabola

(c) an ellipse

(d) none of these

Ans: (a)

Sol: $ R = R_0 A^{1/3} $

$ \frac{R}{R_o} = A^{1/3} $

$ ln \frac{R}{R_o} = \frac{1}{3} ln A $

On comparing with y = m x (straight line) ; where m = 1/3

ln(R/R_{0} ) versus In A will be a straight line