When two resistances are connected in parallel,the equivalent resistance is $\frac{6}{5} \, \Omega$. When one of the resistances is removed,the effective resistance is $2 \, \Omega$. The resistance of the wire removed will be ................ $\Omega$.

What is the equivalent resistance between $A$ and $B$ in the given circuit?

An electric kettle has two heating coils. When one coil is used,water in the kettle boils in $5$ minutes,while when the second coil is used,the same water boils in $10$ minutes. If the two coils,connected in parallel,are used simultaneously,the same water will boil in time:

In the given circuit,the value of $I_{2}$ is: (in $A$)

Four identical resistors are connected in series with a battery,dissipating $20 \ W$ of power. What will be the power dissipated if the same resistors are connected in parallel to the same battery (in $W$)?

$A$ ring is made of a wire having a total resistance $R_0 = 12\,\Omega$. Find the ratio of the lengths $\frac{l_1}{l_2}$ of the two segments of the ring between points $A$ and $B$,as shown in the figure,such that the equivalent resistance $R$ of the sub-circuit between these points is equal to $\frac{8}{3}\,\Omega$.