# GATE2016-1-8

The cross sections of two hollow bars made of the same material are concentric circles as shown in the figure. It is given that $r_3>r_1$ and $r_4 > r_2$, and that the areas of the cross-sections are the same. $J_1$ and $J_2$ are the torsional rigidities of the bars on the left and right, respectively. The ratio $\displaystyle{\frac{J_2}{J_1}}$ is

1. $>1$
2. $<0.5$
3. $=1$
4. between $0.5$ and $1$

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