i] State Ohm's law
ii] Explain the factors on which the resistance of a conductor depends.

Explanation

i] Ohm.s law: When temperature is constant, the potential difference across the ends of a metallic wire (V) is directly proportional to the current (I) flowing through it, i.e., `VpropIorV=RI`
where R is proportionality constant called resistance.
ii] Resistance of a conductor (R) depends on:
1] Length of the conductor (l): Resistance is directly proportional to length of the conductor, i.e., `Rpropl`
(2) Area of cross section of the conductor (A): Resistance is inversely proportional to area of cross section of the conductor, i.e.,
`Rprop1/A`
3] Nature of material of the conductor: Combining 1 and 2, we get,
`Rpropl/AorR=rhol/A`
where `rho` is the constant of proportionality which depends on the nature of material of the conductor.
4] Temperature: The resistance of a conductor increases with increase in temperature.