It is easier to start a car engine on a hot day than on a cold day. This is because the internal resistance of the car battery

Two identical cells give the same current through an external resistance of $2 \Omega$ regardless of whether the cells are connected in series or in parallel. The internal resistance of each cell is: (in $\Omega$)

In an electric circuit,a cell of certain $emf$ provides a potential difference of $1.25\, V$ across a load resistance of $5\, \Omega$. However,it provides a potential difference of $1\, V$ across a load resistance of $2\, \Omega$. The $emf$ of the cell is given by $\frac{x}{10}\, V$. Then the value of $x$ is ..... .

$A$ battery consists of a variable number '$n$' of identical cells,each having an electromotive force '$E$' and internal resistance '$r$',connected in series. The terminals of the battery are short-circuited,and the current '$i$' is measured. Which of the graphs below shows the relationship between '$i$' and '$n$?'

In the network shown,the potential difference between $A$ and $B$ is ................. $V$ $(R = r_1 = r_2 = r_3 = 1 \Omega, E_1 = 3 \, V, E_2 = 2 \, V, E_3 = 1 \, V)$.