What is immaterial for an electric fuse wire?

The equivalent resistance of the infinite network given below is:

In the circuit shown,the potential difference between $X$ and $Y$ will be ............. $V$.

An ammeter and a voltmeter of resistance $R$ are connected in series to an electric cell of negligible internal resistance. Their readings are $A$ and $V$ respectively. If another resistance $R$ is connected in parallel with the voltmeter, what happens to the readings $A$ and $V$?

In the adjoining circuit,the $e.m.f.$ of the cell is $2 \, V$ and the internal resistance is negligible. The resistance of the voltmeter is $80 \, \Omega$. The reading of the voltmeter will be ............. $V$.

The electrochemical equivalents of $Cu$ and $Ag$ are $7 \times 10^{-6}$ and $1.2 \times 10^{-6}$ respectively. If a certain current deposits $14 \ g$ of $Cu$,then the amount of $Ag$ deposited is .......... $g$.