A wire of length $I$ and area $A$ is connected to an ideal battery. The drift speed of electrons is $v.$ If the wire is twisted to half its length, what will be the new drift speed?

In the situation shown each cell has e.m.f. $4 \mathrm{V}$ and internal resistance $1\mathrm{\Omega }$. The maximum power that can be delivered to the variable load resistance $R$ is

Two bulbs $A$ and $B$ are connected as shown. When switch$\text{'}S\text{'}$ is closed then which of them will fuse?

What is the value of resistance ' $R$ ' in circuit, so that the current through $4 \Omega$ resistance is zero?

The equivalent resistance between $A$ and $B$ in the situation shown is

In the situation shown, the currents through $3\mathrm{\Omega }$ and $2\mathrm{\Omega }$ resistances are in the ratio