As shown in the circuit,if a conducting wire is connected between points $A$ and $B$,then the electric current in this wire will flow:

Five equal resistances each of value $R$ are connected in a form shown alongside. The equivalent resistance of the network

Two cells of voltage $10 \ V$ and $2 \ V$ and internal resistances $10 \ \Omega$ and $5 \ \Omega$ respectively,are connected in parallel with the positive end of $10 \ V$ battery connected to the negative pole of $2 \ V$ battery (figure). Find the effective voltage and effective resistance of the combination.

$A$ non-zero current passes through the galvanometer $G$ shown in the circuit when the key $K$ is closed and its value does not change when the key is opened. Then, which of the following statement$(s)$ is/are true?

In the circuit shown in the figure, all the resistances are identical and each has the value $r \ \Omega$. The equivalent resistance of the combination between the points $A$ and $B$ will remain unchanged even when the following pairs of points marked in the figure are connected through a resistance $R$.

$A$ uniform wire of length $200 \, cm$ is connected to a battery, two resistors and a galvanometer as shown in the figure. The galvanometer shows null deflection when the jockey $J$ is at $80 \, cm$ from point $A$. If the resistor $R_2$ is shunted with $30 \, \Omega$ resistance, the galvanometer shows null deflection when the jockey $J$ is at $100 \, cm$ from point $B$. Then the values of $R_1$ and $R_2$ respectively are