Five identical resistors are initially arranged as shown in the figure by solid lines. If two identical resistors are added as shown by the dashed lines,the change in the equivalent resistance between the initial and final configurations is ....... $\Omega$.

In the arrangement of resistances shown below,the effective resistance between points $A$ and $B$ is ............... $\Omega$.

You are given $n$ resistors each of resistance $r$. They are first connected to get the minimum possible resistance. In the second case,they are again connected differently to get the maximum possible resistance. Calculate the ratio between minimum and maximum values of resistance so obtained.

Two identical heaters rated $220\,V, 1000\,W$ are connected in series across a $220\,V$ supply. If the resistance does not change with temperature,the total power consumed by the combination is ............. $W$.

What is series connection of resistors,and what is parallel connection of resistors?

Find the equivalent resistance between points $A$ and $B$.