If a wire of resistance $R$ is melted and recast to half of its length,then the new resistance of the wire will be

State $Ohm's$ law. Write the mathematical representation of $Ohm's$ law. Use this relationship to define $1\, ohm.$ List two disadvantages of connecting different electrical appliances in series.

What is the direction of conventional current?

Is electrostatic potential a scalar quantity or a vector quantity?

Three $V-I$ graphs are drawn individually for two resistors and their series combination. Out of $A, B, C$,which one represents the graph for the series combination of the other two? Give a reason for your answer.

When a high resistance voltmeter is connected directly across an electric bulb,its reading is $2 \ V$. An electric cell is sending a current of $0.4 \ A$ (measured by an ammeter) in the electric circuit.
$(a)$ Draw the circuit.
$(b)$ Find the resistance of the electric bulb.
$(c)$ State the law that is applied for making these calculations. If a graph is plotted between $V$ and $I$,show the nature of the graph obtained.