What is the $SI$ unit of electric charge?

Name a device that can be used to maintain a potential difference across a conductor. Also,draw its circuit symbol.

$A$ current of $0.5\, A$ is drawn by a filament of an electric bulb for $10$ minutes. Find the amount of electric charge that flows through the circuit. (in $C$)

Tungsten is used almost exclusively for filaments of electric bulbs. List two reasons.

Electrical resistivity of a given metallic wire depends upon

An electric bulb is rated at $200 \ V - 100 \ W$. What is its resistance? If five such bulbs burn for $4 \ hours$, what is the total electrical energy consumed? Calculate the cost, if the rate is $50$ paise per unit.