All wires have same resistance and equivalent resistance between $A$ and $B$ is $R$. Now keys are closed, then the equivalent resistance will become
A$\frac{7R}{3}$
B$\frac{7R}{9}$
C$7R$
D$\frac{R}{3}$
Diffcult
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A$\frac{7R}{3}$
a
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