The value of $I$ in the figure shown below is: (in $\text{ A}$)

The reading of the ammeter in amperes for the following circuit is:

$A$ Wheatstone bridge has the resistances $10 \Omega, 10 \Omega, 10 \Omega$ and $30 \Omega$ in its four arms. What resistance joined in parallel to the $30 \Omega$ resistance will bring it to the balanced condition (in $\Omega$)?

Choose the correct circuit which can achieve the bridge balance.

Refer to the figure given below. The values of $I_1, I_2$ and $I_3$ are . . . . . . .

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