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:

Two resistances $r_1$ and $r_2$ $(r_1 < r_2)$ are joined in parallel. The equivalent resistance $R$ is such that

The equivalent resistance of three unequal resistors connected in parallel is $1 \ \Omega$. If the ratio of two of them is $1:2$ and all resistance values are integers,what is the value of the largest resistor in ohms?

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 ..............$V$.

$A$ circuit consists of five identical conductors,each of resistance $1 \ \Omega$,as shown in the figure. Two similar conductors are added as indicated by the dotted lines. The ratio of the equivalent resistances before and after the addition is:

In the given circuit,the equivalent resistance between $A$ and $B$ is (in $\Omega$)