Calculate the conductance and conductivity of the material of a wire of resistance $0.01 \mathrm{\Omega }$, area of cross-section ${10}^{-4}{ \mathrm{m}}^2$ and length $0.1 \mathrm{m}$
 

In the given network of Fig. $5.133,{\mathrm{R}}_1=100$$\mathrm{\Omega },{\mathrm{R}}_2={\mathrm{R}}_3=50{\mathrm{\Omega R}}_4=$$75 \mathrm{\Omega }$ and $\mathrm{E}=6.0 \mathrm{V}$ Find the currents in each resistor.

Calculate the equivalent resistance between the points $\mathrm{A}$ and $\mathrm{B}$ of the following network of conductors in Fig.

In the circuit shown, Fig.  the length of the wire $\mathrm{A} \mathrm{B}$ is $400 \mathrm{cm}$. Where should the jockey, $J$ be placed so that the galvanometer shows zero deflection?