Kirchhoff's first law,$i.e.$,$\Sigma i = 0$ at a junction,is based on the law of conservation of:

The electric current $i$ in the circuit shown is (in $\text{ A}$)

Kirchhoff's first law $(\sum i = 0)$ and second law $(\sum iR = \sum E)$,where the symbols have their usual meanings,are respectively based on:

If the charge on the capacitor is $1 \text{ mC}$ in the given circuit,then $\frac{R_1 R_2}{R_3} = \ldots \ldots \ldots \Omega$.

The resistances of the four arms $P, Q, R$ and $S$ in a Wheatstone's bridge are $10 \, \Omega$, $30 \, \Omega$, $30 \, \Omega$ and $90 \, \Omega$, respectively. The e.m.f. and internal resistance of the cell are $7 \, V$ and $5 \, \Omega$ respectively. If the galvanometer resistance is $50 \, \Omega$, the current drawn from the cell will be ............... $A$.

See the electrical circuit shown in the adjoining figure. Which of the following equations is a correct equation for it?