Kirchhoff's first law is based on the principle of 

Five resistance are connected to form a bridge as show in the given circuit diagram. The effective resistance between the points $A$ and $B$ is nearly

A current of $2\mathrm{A}$ enters into the arrangement of resistors given below at $A$ and leaves it at $C$. The potential difference between the points $B$ and $D$ i.e. $V_B-V_D$ will be

Given below is an arrangement of resistors in the form of a Wheatstone's bridge. For the bridge to be balanced, the unknown resistance $X$ should be