In the given figure,when key $A$ is opened,the reading of the ammeter $A$ will be ........... $A$.

In the circuit shown,the cells $A$ and $B$ have negligible internal resistances. For $V_A = 16 \ V$,$R_1 = 600 \ \Omega$,and $R = 200 \ \Omega$,the galvanometer shows no deflection. The value of $V_B$ is $...V$.

The figure shows a network of resistors and a battery. If $1\,A$ current flows through the branch $CF$,then find the $emf$ $E$ of the battery. (in $,V$)

The figure shows a network of resistors and a battery. If $1 \ A$ current flows through the branch $CF$,then the $emf$ $E$ of the battery is ............... $V$.

An electric current is passed through a circuit containing two wires of the same material,connected in parallel. If the lengths and radii of the wires are in the ratio of $4/3$ and $2/3$ respectively,then the ratio of the currents passing through the wires will be:

If the heat produced in the $5 \, \Omega$ resistor is $10 \, \text{cal/sec}$, then how much heat in $\text{cal/sec}$ is produced in the $4 \, \Omega$ resistor?