The equivalent resistance between points $A$ and $B$ of the following electric circuit will be $.........$
$4\, \Omega$
$8\, \Omega$
$2\, \Omega$
$16 \,\Omega$
Define electric power. Give its $SI$ unit.
In an experimental set$-$up as shown below, a piece of silver was placed touching points $A$ and $B .$ Next time it was replaced by a piece of wood. In which case did the bulb glow ? Give reason to justify the observation.
A bulb gets dimmer for a moment when a geyser, connected across the same source is switched on. Why ?
$(a)$ Calculate the resistance of the wire using the graph.
$(b)$ How many $176 \,\Omega$ resistors in parallel are required to carry $5\, A$ on a $220\, V$ line ?
$(c)$ Define electric power. Derive relation between power, potential difference and resistance.
Why is much less heat generated in long electric cables than in filaments of electric bulbs ?