Which of the following materials are generally used for electrical transmission lines due to their low resistivity?
Copper and aluminium
Copper and aluminium are commonly used in electrical transmission lines due to their low resistivity, high conductivity, and cost-effectiveness. - Copper has excellent conductivity and is widely used in electrical wiring. - Aluminium, although slightly less conductive than copper, is lighter and more cost-effective, making it suitable for overhead power lines.
Which of the following expressions correctly represents the SI unit of electric charge, the Coulomb ($C$), in terms of other fundamental or derived SI units?
Two point charges, $Q_1 = +3 \mu C$ and $Q_2 = -8 \mu C$, are placed at a certain distance apart. They attract each other with a force of $48 N$. If each charge is given an additional charge of $+6 \mu C$, what will be the magnitude and nature of the new force between them?