CBSE · Class 10 · Science · ElectricityOn what factors does the resistance of a cylindrical conductor depend? Explain each factor clearly.

The resistance of a uniform cylindrical conductor depends upon several specific physical properties of the conductor. First, the resistance ($R$) is directly proportional to its length ($l$); longer conductors offer more resistance because electrons collide more frequently with atoms as they traverse the wire. Second, the resistance is inversely proportional to the cross-sectional area ($A$) of the conductor; thicker wires have a larger area, providing a wider path for electrons and thus reducing resistance. Third, the resistance depends directly on the nature of the material of the conductor, which is quantified by a property called resistivity ($\rho$). Materials like copper and silver have very low resistivity and are good conductors, whereas alloys and insulators have high resistivity. Finally, resistance also depends on temperature, generally increasing with a rise in temperature for pure metals due to enhanced thermal vibrations.