State Kirchhoff's junction law and loop law.

The resistances of four arms of the Wheatstone bridge are given in the circuit given below.

$R_{\mathit{A}\mathit{B}}=100 \mathrm{\Omega }, R_{\mathit{B}\mathit{C}}=10 \mathrm{\Omega },$ $R_{\mathit{C}\mathit{D}}=5 \mathrm{\Omega } \mathrm{and} R_{\mathit{D}\mathit{A}}=60 \mathrm{\Omega }$

A galvanometer of $15 \mathrm{\Omega }$ is connected between the terminals $B$ and $D$. Calculate the current flowing through the galvanometer. The potential difference between terminals $A$ and $C$ is given as $10 \mathrm{V}$. 

In the Fig., what is the potential difference $V_d-V_c$ between the points $d$ and $c$ if ${\mathcal{E}}_1=4.0 \mathrm{V}, {\mathcal{E}}_2=1.0 \mathrm{V}, R_1=R_2=10 \mathrm{\Omega },$ and$R_3=8.0 \mathrm{\Omega }$ and the battery is ideal?

Find the emf of the battery shown in figure.