Positive charges flow from high potential to low potential.

$(a)$ 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?

Three resistors $R_{1} = 5 \Omega$,$R_{2} = 10 \Omega$,and $R_{3} = 30 \Omega$ are connected in parallel to a $12 \; V$ battery. Which resistor will have the highest current flowing through it?

Three $2 \,\Omega$ resistors,$A, B$ and $C,$ are connected as shown in the figure. Each of them dissipates energy and can withstand a maximum power of $18 \,W$ without melting. Find the maximum current $I$ that can flow through the circuit.

Study the following circuit and answer the following questions:
$(i)$ State the type of combination of the two resistors in the circuit.
$(ii)$ How much current would flow through:
$(a)$ $10 \, \Omega$ resistor and
$(b)$ $15 \, \Omega$ resistor?
$(iii)$ What would be the ammeter reading?

$Ohm's$ law is a relation between the power used in a circuit to the current and the potential difference.