If all the resistors shown in the circuit have a value of $2\, \Omega$ each, find the equivalent resistance between points $A$ and $B$.

$A$ circular coil of total resistance $40 \Omega$ has two points '$P$' and '$Q$' on its circumference. The arc length between '$P$' and '$Q$' is such that the coil is divided into two parts with resistances $30 \Omega$ and $10 \Omega$. These points are connected to a $16 \text{ V}$ battery with an internal resistance of $0.5 \Omega$. What is the value of the current '$I$' flowing through the circuit (in $\text{ A}$)?

Two bulbs,one of $50\, W$ and another of $25\, W$,are connected in series to the mains. The ratio of the currents through them is:

There are $8$ equal resistances $R$. Two are connected in parallel,and such four groups are connected in series. The total resistance of the system will be:

When a wire of uniform cross-section $a$,length $ℓ$,and resistance $R$ is bent into a complete circle,the resistance between any two diametrically opposite points will be .......

The total power dissipated (in $watt$) in the circuit shown is