Question

When the switch of the circuit is turned on, the filament of the bulb glows instantaneously because:

• A. the electrons coming from the power source move fast through the initially empty filament.
• B. the filament may be old having low resistance.
• C. electric field is established instantaneously across the filament which pushes the electrons.
• D. free electrons in the filament travel with the speed of light.

Hint:

The filament's resistance is a critical factor in determining how quickly it heats up when the circuit is closed. Lower resistance leads to a quicker rise in temperature, causing immediate glowing.

Answer 1

The Correct Option is B

When the switch is turned on, an electric field is applied across the filament. The filament's resistance plays a key role. A lower resistance allows electrons to flow more easily, resulting in the filament heating up quickly, which causes it to glow instantaneously. Hence, the filament having low resistance helps in this effect.