Three identical cells are connected in parallel across $AB.$ Net emf across $AB$ is

When current supplied by a cell to a circuit is $0.3 \mathrm{A},$ its terminal potential difference is $0.9 \mathrm{V}.$ When the current supplied becomes $0.25 \mathrm{A},$ its terminal potential difference becomes $1.0 \mathrm{V}.$ The internal resistance of the cell is

Current $I$ in the network shown in figure is

Value of the resistance $R$ in the figure is

Current through the $25 \mathrm{\Omega }$ resistor as shown in figure is

In the following diagram, the lengths of wires $AB$ and $BC$ are equal but the radius of wire $AB$ is double to that of $BC.$ The ratio of potential gradient on wires $AB$ and on $BC$ will be (wires are made of same material)

Three identical bulbs are connected as shown in figure. When switch $S$ is closed, the power consumed in bulb $B$ is $P.$ What will be the power consumed by the same bulb when switch $S$ is opened?