The length of a metallic wire is increased by $$20 \%$$ and its area of cross section is reduced by $$4 \%$$. The percentage change in resistance of the metallic wire is __________.

In the given circuit, the value of $$\left| {{{{\mathrm{I_1}} + {\mathrm{I_3}}} \over {{\mathrm{I_2}}}}} \right|$$ is _____________

In an experiment to find emf of a cell using potentiometer, the length of null point for a cell of emf $$1.5 \mathrm{~V}$$ is found to be $$60 \mathrm{~cm}$$. If this cell is replaced by another cell of emf E, the length-of null point increases by $$40 \mathrm{~cm}$$. The value of $$E$$ is $$\frac{x}{10} V$$. The value of $$x$$ is ____________.

Two identical cells, when connected either in parallel or in series gives same current in an external resistance $$5 ~\Omega$$. The internal resistance of each cell will be ___________ $$\Omega$$.