What is the value of the current flowing through the galvanometer in the balanced condition of a Wheatstone bridge?

The Wheatstone bridge shown in the figure gets balanced when the carbon resistor used as $R_1$ has the colour code (Orange,Red,Brown). The resistors $R_2$ and $R_4$ are $80 \, \Omega$ and $40 \, \Omega$,respectively. Assuming that the colour code for the carbon resistors gives their accurate values,the colour code for the carbon resistor used as $R_3$ would be

Five resistances are connected as shown in the figure. The effective resistance between points $A$ and $B$ is

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

As shown in the figure,a $5\,V$ battery with $2\,\Omega$ internal resistance and a $2\,V$ battery with $1\,\Omega$ internal resistance are connected to a $10\,\Omega$ resistor. The current flowing through the $10\,\Omega$ resistor is:

Twelve equal resistors,each of resistance $R$,are connected to form a skeleton cube. The equivalent resistance between two diagonally opposite corners is: