What is the lowest resistance that can be obtained by combining four coils of resistances $4\, \Omega, 8\, \Omega, 12\, \Omega$ and $24\, \Omega$?

What is the electric charge passing through a cross-sectional area of the conductor per unit time called?

$(a)$ Why is the series arrangement not used for domestic circuits?
$(b)$ Why is tungsten used almost exclusively for the filament of electric lamps?
$(c)$ Why are the conductors of electric heating devices,such as bread toasters and electric irons,made of an alloy rather than a pure metal?
$(d)$ Why are copper and aluminium wires usually employed for electricity transmission?
$(e)$ Why does the cord of an electric heater not glow while the heating element does?

$(a)$ Explain why a conductor offers resistance to the flow of current.
$(b)$ Differentiate between conductor,resistor,and resistance.

$A$ wire of resistance $10 \, \Omega$ is bent in the form of a closed circle. What is the effective resistance between the two points at the ends of any diameter of this circle?

What is the resistance of insulating materials?