$A, B$ and $C$ are voltmeters of resistance $R, 1.5R$ and $3R$ respectively as shown in the figure. When some potential difference is applied between $X$ and $Y$,the voltmeter readings are $V_A, V_B$ and $V_C$ respectively. Then

The potential difference $V_B - V_A$ in the network shown is ............. $V$.

If two bulbs of wattage $25\, W$ and $100\, W$ respectively,each rated at $220\, V$,are connected in series with a supply of $440\, V$,then which bulb will fuse?

When the terminals of a cell are connected by a wire of resistance $4 \Omega$,the potential difference across the cell is $1.6 \text{ V}$. If a wire of the same resistance is connected in parallel with the first,the potential difference becomes $1.33 \text{ V}$. The emf and internal resistance of the cell are respectively

$A$ $DC$ source with internal resistance $R_0$ is connected to three identical resistors each of resistance $R$ as shown in the figure. If the thermal power generated in the circuit is highest,then

If the resistance of the voltmeter is $10000 \,\Omega$ and the resistance of the ammeter is $2 \,\Omega$,find the value of $R$ when the voltmeter reads $12 \,V$ and the ammeter reads $0.1 \,A$.