What will be the equivalent resistance between the two points $A$ and $D$ in the given circuit (in $\Omega$)? (All resistors are $10 \ \Omega$ each.)

$A$ $100\, W$ bulb $B_1$,and two $60\, W$ bulbs $B_2$ and $B_3$,are connected to a $250\, V$ source,as shown in the figure. Now $W_1, W_2$ and $W_3$ are the output powers of the bulbs $B_1, B_2$ and $B_3$,respectively. Then

$A$ car has a fresh storage battery of emf $12 \, V$ and internal resistance $2 \times 10^{-2} \, \Omega$. If the starter motor draws a current of $80 \, A$, then the terminal voltage when the starter is $ON$ is: (in $V$)

The potential difference across the $40\,\Omega$ resistor in the given circuit is ............ $V$.

What is immaterial for an electric fuse wire?

The potential difference across the terminals of the battery shown in the figure is ................. $V$. ($r$ = internal resistance of the battery)