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

Calculate the potential difference between $A$ and $B$ in the given circuit in $volt$.

The current through the $1 \Omega$ resistance in the following circuit is (in $A$)

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

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

State the principle of a Wheatstone bridge.