The reading of the ammeter in the following circuit is ................... $A$ (Assuming an ideal ammeter).

Eight resistances each of resistance $5\,\Omega$ are connected in the circuit as shown in the figure. The equivalent resistance between $A$ and $B$ is

The equivalent resistance between the points $A$ and $D$ is ................ $\Omega$.

$A$ wire of resistance $100 \Omega$ is stretched so that its length increases by $20 \%$. The stretched wire is then bent in the form of a rectangle whose length and breadth are in the ratio $3: 2$. The effective resistance between the ends of any diagonal of the rectangle is (in $\Omega$)

Two uniform wires $A$ and $B$ are of the same metal and have equal masses. The radius of wire $A$ is twice that of wire $B$. The total resistance of $A$ and $B$ when connected in parallel is

Write the equation for the equivalent resistance of $n$ resistors connected in series and the equation for the equivalent resistance of $n$ resistors connected in parallel.