The resistivity of a material does not change if:

What is meant by an electric circuit? Draw a circuit diagram to show an electric circuit comprising a battery of two cells,a resistor,an ammeter,and a plug key when the circuit is closed.

State Ohm's law. How can it be verified experimentally? Does it hold good under all conditions? Comment.

The resistivity of all pure metals increases with an increase in temperature.

If $2 \times 10^{-3} \text{ J}$ of work is done in moving a particle carrying a charge of $10 \times 10^{-6} \text{ C}$ from infinity to a point $P$, what will be the potential at the point $P$ (in $\text{ V}$)?

What is meant by resistance of a conductor? Name and define its $SI$ unit. List the factors on which the resistance of a conductor depends. How is the resistance of a wire affected if
$(i)$ its length is doubled,
$(ii)$ its radius is doubled?