Question

why does resistance of light bulb which is not glowing is low.

Answer 1

It depends on the connection of the bulb.

if u connect them in series, then bulb with higher resistance (lower wattage rating) will glow brighter than low resistance bulb.

Proof- In series use formula P= (I^2)*R, where I is constant.

If u connect them in parallel, then bulb with lower resistance (higher wattage rating bulb) will glow brighter than high resistance bulb.

Proof- In parallel use formula P= (V^2)/R, where V is constant.

Answer 2

Incandescent light bulbs have a small filament which when heated begins to glow and emit light. The reason the filament heats up is because it has a high resistance, which means that as electrons move through the filament, they lose a lot of energy, and so its resistance becomes low.

 

Hope it helped you.....