One end each of a resistance $r$,a capacitor $C$,and a resistance $2r$ are connected together. The other ends are respectively connected to the positive terminals of batteries $P$,$Q$,and $R$ having emfs $E$,$E$,and $2E$. The negative terminals of the batteries are then connected together. In this circuit,with steady current,the potential drop across the capacitor is:

An electric toaster uses nichrome for its heating element. When a negligibly small current passes through it,its resistance at room temperature $(27.0^{\circ} C)$ is found to be $75.3\; \Omega$. When the toaster is connected to a $230\; V$ supply,the current settles,after a few seconds,to a steady value of $2.68\; A$. What is the steady temperature (in $^{\circ} C$) of the nichrome element? The temperature coefficient of resistance of nichrome averaged over the temperature range involved is $1.70 \times 10^{-4}\; ^{\circ} C^{-1}$.

Inside a superconducting ring,six identical resistors each of resistance $R$ are connected as shown in the figure. The equivalent resistance$(s)$:

Identical resistors of resistance $R$ are connected as shown in the figure. Find the equivalent resistance between $x$ and $y$.

The current inside a copper voltameter:

In the circuit shown,the resistances are given in ohms and the battery is assumed ideal with $emf$ equal to $3.0 \ V$. The resistor that dissipates the most power is