The terminal voltage $V$ across a battery of $emf$ $E$ and internal resistance $r$ can be:

$A$ wire of resistance $10 \, \Omega$ is bent to form a circle. $P$ and $Q$ are points on the circumference of the circle dividing it into a quadrant and are connected to a battery of $3 \, V$ and internal resistance $1 \, \Omega$ as shown in the figure. The currents in the two parts of the circle are

Three identical resistors are connected in series,and the total power consumed is $10 \, W$. If they are connected in parallel,what will be the total power consumed in $W$?

An electric kettle has two coils. When one coil is switched on,the tea gets heated in $10 \, \text{min}$. When the other coil is switched on,the same amount of tea gets heated in $40 \, \text{min}$. If both coils are connected in parallel,how long will it take to heat the same amount of tea (in $, \text{min}$)?

There are two electric bulbs of $40\, W$ and $100\, W$. Which one will be brighter when first connected in series and then in parallel?

If $E = at + bt^2$,what is the temperature of inversion?