When a wire of uniform cross-section $a$,length $l$ and resistance $R$ is bent into a complete circle,what is the resistance between any two diametrically opposite points?

Three identical bulbs $B_1, B_2$ and $B_3$ are connected to the mains as shown in the figure. If $B_3$ is disconnected from the circuit by opening switch $S$,then the incandescence of bulb $B_1$ will

For the circuit shown in the figure,the power delivered by the battery is ................ $W$.

$A$ wire of cross-section area $A$,length $L_1$,resistivity $\rho_1$ and temperature coefficient of resistivity $\alpha_1$ is connected to a second wire of length $L_2$,resistivity $\rho_2$,temperature coefficient of resistivity $\alpha_2$ and the same area $A$,so that the wires carry the same current. The total resistance $R$ is independent of temperature for small temperature changes if (Thermal expansion effect is negligible):

In the circuit given, $E = 6.0 \, V$, $R_1 = 100 \, \Omega$, $R_2 = R_3 = 50 \, \Omega$, and $R_4 = 75 \, \Omega$. The equivalent resistance of the circuit, in $\Omega$, is:

$A$ bulb rated at $(100\,W, 200\,V)$ is used on a $100\,V$ line. The current in the bulb is