A steady current $I$ is set up in a wire whose cross-sectional area decreases in the direction of the flow of the current. Then, as we examine the narrowing region,


 

The velocity of an electron at point $A$ is $V_0$, where the cross-sectional area is$a$. The velocity of the electron at the end of contraction at point $B$, where the cross-sectional area is $2a$, is $V_1$. Find the correct option.

A battery of $10 \mathrm{V}$ and negligible internal resistance is connected across the diagonally opposite corner of a cubical network consisting of $12$ resistors each of resistance $1 \mathrm{\Omega }$. The total current $I$ in the circuit external to the network is:

In the given circuit, all resistors are of $R \mathrm{\Omega }$ each. If a wire is connected between $C$ and $B$, then, the ratio of equivalent resistance between $AB$ of original circuit to new circuit formed is,

The effective resistance between points $\mathrm{A}$ and $\mathrm{B}$ of infinite network is