$A$ square-shaped wire with a resistance of $3\, \Omega$ for each side is bent to form a complete circle. The resistance between two diametrically opposite points of the circle in units of $\Omega$ will be:

Two wires of equal diameters with resistivities ${\rho _1}$ and ${\rho _2}$ and lengths $x_1$ and $x_2$ are joined in series. The equivalent resistivity of the combination is

Consider the circuit shown below where all resistors are $1 \,k\Omega$. If a current of magnitude $1 \,mA$ flows through the resistor marked $X$,the potential difference measured between points $P$ and $Q$ is ..............$V$.

Two bulbs,one of $200 \,W$ and the other of $100 \,W$ are connected in series with a $100 \,V$ battery which has no internal resistance. Then,

The equivalent resistance between the points $A$ and $B$ is:

Three resistances of $1\, \Omega$ each are connected in parallel. Such a connection is then connected in series with a $\frac{2}{3}\, \Omega$ resistor. The resultant resistance will be ........... $\Omega$.