Two resistors of resistance $2 \,\Omega$ and $4 \,\Omega$ when connected to a battery will have:

$(a)$ 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?

The $I-V$ graph for a given metallic wire at three different temperatures is shown. Which of these represents the highest temperature?

When three resistors of $5 \Omega$,$10 \Omega$,and $30 \Omega$ are connected in parallel in a circuit,what will be the equivalent resistance?

$A$ thick wire and a thin wire of the same material are successively connected to the same circuit to find their respective resistance. Which one will have lower resistance? Give reason.

$1 \; kWh = \ldots \ldots \ldots \; \text{watt-seconds}$