Three electric bulbs of $200\,W, 200\,W$ and $400\,W$ are shown in the figure. The resultant power of the combination is ................ $W$.

Three resistors each of $4\,\Omega$ are connected together to form a network. The equivalent resistance of the network cannot be ............ $\Omega$.

Some electric bulbs are connected in series across a $220\, V$ supply in a room. If one bulb is fused,then the remaining bulbs are connected again in series across the same supply. The illumination in the room will

Two known resistances of $R \ \Omega$ and $2R \ \Omega$ and one unknown resistance $X \ \Omega$ are connected in a circuit as shown in the figure. If the equivalent resistance between points $A$ and $B$ in the circuit is $X \ \Omega$, then the value of $X$ is . . . . . . $\Omega$.

The current $I$ drawn from the $5 \text{ V}$ source will be ............... $A$.

$A$ wire of length $25 \ m$ and cross-sectional area $5 \ mm^2$ having resistivity of $2 \times 10^{-6} \ \Omega \ m$ is bent into a complete circle. The resistance between diametrically opposite points will be (in $\Omega$)